Programme and abstracts
Click on a talk or poster title to view the abstract.
Monday 30 March
Tuesday 31 March
Wednesday 1 April
List of posters
Abstracts
Monday 30 March
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Tuesday 31 March
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Wednesday 1 April
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Posters
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Abstracts
Ahmed F. Al-Refaie
Presentation type: talk
Title:
Some like H2CO hot: The Exomol Project
Abstract:
The standard way of characterising the atmospheres of exoplanets and cool stars is through forward modelling. Forward modelling can infer the composition and temperature/pressure profile by producing a synthetic spectra that close matches those observed. Such modelling requires spectroscopic data of atoms and molecules relevant to these atmospheres. Temperature ranges of hot Jupiters and cool stars allow for a significant composition of molecules in their atmospheres. Molecules have extremely complex and rich spectral structures that become increasingly dense in transitions as their temperatures increase. Experimentally acquiring and assigning spectroscopic data at high temperatures and a wide range of frequencies can pose a wide range of challenges and difficulties. An alternative solution to this is to build the line-list through theoretical means, this is the goal of the Exomol project [1]. The Exomol project aims to provide a comprehensive line-list for a range of molecules at high temperatures relevant to exoplanets and cool stars. This talk will describe the process and challenges faced in producing our recent hot line-list AYTY [2] for the molecule formaldehyde. Production and refinement of the potential energy surface, solving the Schroedinger equation variationally using TROVE [3] and the evaluation of over 10 billion transitions will be discussed. Formaldehyde has a range of astrophysical phenomena that makes it interesting enough to be considered in the Exomol project. It is abundant in the interstellar medium (ISM)[4]. It is a precursor to many complex organic molecules in the ISM that include interstellar glycolaldehyde[5] and amino acids [6]. Multiple detections in comets [7] and proto-planetary discs [8]. Detection of masers in 19 extra-galactic sources [9] and finally, multiple early Earth models suggests it may act as a possible bio-marker [10,11].
[1] J. Tennyson and S. N. Yurchenko. MNRAS , 425, 21-33 , 2012 [2] A. F. Al-Rafaie, S. N. Yurchenko, A. Yachmenev, and J. Tennyson. MNRAS, 2015. [3] S. N. Yurchenko, W. Thiel, and P. Jensen. J. Mol. Spectrosc., 245, 126-140, 2007. [4] W. D. Langer. ApJ, 210, 328-333, 1976 [5] J. M. Hollis, F. J. Lovas, and P. R. Jewell. ApJ, 540, 107-L110, 2000. [6] W. A. Schutte. Adv. Space Res., 30, 1409-1417, 2002. [7] D. Bockelee-Morvan and J. Crovisier. . A&A, 264, 282-291, 1992. [8] K. I. Oberg et. al. ApJ, 720,480-493, 2010. [9] J. G. Mangum, J. Darling, K. M. Menten, and C. Henkel. ApJ, 673, 832-846, 2008. [10] M. Neveu, H. Kim, and S. A. Benner. Astrobiology, 13,391-403, 2013. [11] N. Goldman and I. Tamblyn. J. Phys. Chem. A, 117,5124-5131, 2013.
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Richard Alexander
Presentation type: institutional summary
Title:
Exoplanet research at the University of Leicester
Abstract:
I will present a summary of the exoplanet research programme at the University of Leicester. I will give an overview of our on-going projects, spanning observational, theoretical and instrumental research, point out some recent highlights, and discuss the future direction(s) of our work on exoplanets.
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David Armstrong
Presentation type: talk
Title:
Planets and Variables with K2
Abstract:
With the recent revival of the Kepler spacecraft in the form of K2, we have a chance to find small planets around sometimes much brighter stars than allowed by the original mission, albeit on shorter periods. K2 presents its own challenges to detection, particularly from the motion of the spacecraft. I will describe some features of the K2 data, and show how we have been dealing with these to produce detrended K2 lightcurves at Warwick. I will also show some results for both planets and variable stars, and describe the state of our search for new candidate planets in the data.
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Eleanor Bacchus
Presentation type: poster
Title:
Observing HD 114174 B as a demonstration of high contrast imaging spectroscopy with Project 1640
Abstract:
Project 1640 is a direct imaging survey with the ability to simultaneously obtain images and low resolution spectra of faint companions around nearby stars. The spectra span the H and J bands in the near infrared and enable the detection of broad molecular absorption lines, allowing basic atmospheric modelling to be done and helping to characterise imaged companions. We are currently conducting a survey of near A-F type stars with the aim of detecting young, Jupiter mass planets at separations of around 1”-2” from their host stars.
We have also undertaken several observations of known companions, in order to both test our pipeline and provide spectra and further astrometric data to help refine photometric and orbital parameters for these objects. One of these is the TRENDS object HD 114174 B – a faint white dwarf around a nearby G star. We present astrometry and spectroscopy of this object as an example of what can be achieved with a method that is going to play an important role in the future characterisation of exoplanets.
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Isabelle Baraffe
Presentation type: institutional summary
Title:
Exoplanets made in Exeter: detection, characterisation and modelling
Abstract:
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Adrian Barker
Presentation type: talk
Title:
Tides in giant planets and stars
Abstract:
Tidal interactions between short-period planets and their host stars are thought to play an important role in the evolution of the planetary orbit and stellar spin. In particular, the fate of short-period planets is determined by the dissipation of tidal flows inside their stars, and the observational preponderance of circular orbits amongst short-period planets (relative to those with wider orbits) is thought to be explained by the dissipation of tidal flows inside these planets. I will review our current understanding of the mechanisms of tidal dissipation inside both planets and stars, and will present the results of recent and ongoing theoretical work aimed at understanding the mechanisms of tidal dissipation using simulations from first principles. The importance of various mechanisms in explaining the observations will be discussed.
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John Barnes
Presentation type: talk
Title:
Starspot distributions on fully convective M dwarfs: implications for radial velocity planet searches
Abstract:
Upcoming precision radial velocity surveys will search for low mass planets orbiting the lowest mass stars. The contribution of photospheric activity to astrophysical jitter must therefore be considered when characterising planetary radial velocity signatures. I will present Doppler images of the latest M dwarfs to date, GJ 791.2A (M4.5V) and LP 944-20 (M9V). The time series spectra of the stars reveal numerous line profile distortions which we interpret as starspots. Although starspot activity is stronger at high latitudes, we reconstruct spots distributed at a range of phases and latitudes. The low contrast and uniform distribution or absence of spots at low latitudes explain the relatively low amplitude photometric variability seen in M dwarfs. The reconstructed starspot patterns yield r.m.s. radial velocity jitter of order 100 m/s. Since M dwarfs in the M4.5-M9V spectral range exhibit mean vsini = 5-16 km/s, radial velocity surveys targeting this population will likely need to find methods to effectively remove starspot jitter.
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Emma J Barton
Presentation type: talk and poster
Title:
Implementing Pressure Broadening in Molecular Line Lists for Application to Extrasolar Planets
Abstract:
ExoMol has previously calculated high resolution temperature dependent cross-sections for selected molecules according to Hill et al. (2013). Pressure dependence is now being implemented for five molecules expected to be of importance in the atmospheres of Hot Jupiter's, H2O, CO2, CO, CH4 and NH3.
Unfortunately there is an overall lack of accurate pressure broadening parameters for high temperature molecular lines and broadening by relevant species, namely H2 and He. For the most part parameters are extrapolated from room temperature and pressure and small quantum numbers or approximated using air broadening parameters given in HITRAN with the exception of H2O. For this molecule a data set of H2 and He pressure broadening parameters for molecular lines of importance in the temperature range 500 – 2000 K has been computed by Nina Lavrentieva and Anna Dudaryonok using semi-empirical methods.
Presented is a summary of the work done to date including an investigation into the influence of pressure broadened width accuracy on Exoplanet spectral models using Tau-REx.
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Beth Biller
Presentation type: institutional summary
Title:
Exoplanets and Astrobiology at Edinburgh
Abstract:
Over the last few years, we have been building a dynamic and growing exoplanets and astrobiology group at the University of Edinburgh. Dr. Ken Rice (along with postdoc Dr. Eric Lopez and PhD student Cassandra Hall) leads theoretical work regarding the formation and stability of planetary systems, including simulations of self-gravitating discs, the ultimate fate of self-gravitating disc fragments, the dynamical evolution of planetary systems, and the formation and evolution of super-Earths and sub-Neptunes. Dr. Beth Biller (along with postdoc Dr. Mariangela Bonavita and PhD student Johanna Vos) leads observational direct imaging studies of exoplanets, with a particular focus on the statistical analysis of large direct imaging exoplanet surveys, variability of young free-floating brown dwarfs and planets, and variability of exoplanet companions to young stars. Professor Charles Cockell is the director of the UK Centre for Astrobiology and leads a group studying life in extreme environments, in particular the interaction of microbes with minerals and the function and diversity of microbes in rocky environments. Professor Paul Palmer is a climate scientist specialising primarily in Earth atmosphere modeling, but is branching out into modeling of exoplanet and brown dwarf atmospheres along with PhD student Jack Yates.
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Jakub Bochinski
Presentation type: talk
Title:
Direct evidence for an evolving dust cloud from the exoplanet KIC 12557548 b
Abstract:
A super-mercury, known as KIC 12557548 b, has been hypothesised to be the source of the asymmetric and highly variable transit-like signature visible in the light curve of the star KIC 12557548. I will present simultaneous multi-colour optical photometry of this system obtained in July 2013 with ULTRACAM on the William Herschel Telescope. It reveals, for the first time, the colour dependence of the transit depth and provides direct evidence in favour of KIC 12557548 b being a disrupting low-mass rocky planet, feeding a transiting dust cloud. If the grain size in the transiting dust cloud changes as the transit depth changes, the extinction efficiency is expected to change in a wavelength- and composition-dependent way. Observing a change in the wavelength-dependent transit depth would offer an unprecedented opportunity to determine the composition of the disintegrating rocky body KIC 12557548 b.
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Mariangela Bonavita
Presentation type: talk
Title:
On the Gaia-SPHERE Synergy for Improved Characterization of the Orbital Architecture of Wide-Separation Giant Planet Systems
Abstract:
Even though giant planets represent the majority of the planets detected so far, we are far from having a clear picture of their occurrence, variety, and properties. RV and transit explorations are indeed still limited to planets in relatively close orbits, while current direct imaging searches probe the outermost regions of the planetary systems in the early phases of formation, when the planet/star contrast is favorable because young planets are still hot.
New and more precise dedicated instruments (such as SPHERE at the VLT and GPI at the GEMINI south) are becoming available and are expected to dramatically improve the number of detections of young planets in wide orbits. Imaging allows a comprehensive view of systems, determining planetary orbits and an extensive spectro-photometric characterization, but the mass determination of these planets relies on the prediction of the evolutionary models which provide a mass estimate given the age and the observed luminosity. These models are uncertain and have not been calibrated so far by means of observations. This requires independent dynamical measurements of the mass of the planets. Precise RV measurement are extremely difficult for the imaging targets, because of the high level of activity expected for these young stars, leaving astrometry the best possible way to obtain the needed dynamical constraints. The current precision for astrometric measurements is not high enough to achieve this goal, but the advent of the ESA Gaia satellite will very soon change this. Here we present results from a detailed set of numerical simulations (using actual target lists and synthetic planet populations) aimed at gauging the elements of the parameter space of orbital architectures and masses of wide-separation giant planet systems that might be constrained to a significant extent by combining SPHERE imaging and astrometric data and Gaia astrometry. We focus in particular on the characterization of systems detected by both instruments or in one channel only. The results are expressed in the form of metrics characterizing, for example, the achievable precision in mass determination from the combined techniques.
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David Brown
Presentation type: talk and poster
Title:
Constraints on circumbinary planet orbits from Kepler single transit events
Abstract:
All of the known transiting circumbinary planets orbit very close to coplanar with their host binaries. But circumbinary systems are not, a priori, limited to this configuration; misaligned systems are likely to exist, and their discovery and characterisation of would shed light on the dynamical history of planets on circumbinary orbits, and on the possible migration mechanisms that might be acting on such complex systems.
We have identified candidate misaligned circumbinary systems within Kepler data. These candidates show single, non-periodic transits that can be used to place constraints on possible orbital configurations for the third body for given binary star parameters. We have developed tools to identify and model possible planetary orbits, and will present preliminary results for representative binary star cases that illustrate our ability to constrain the planet's orbital period and inclination.
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Philip Carter
Presentation type: institutional summary
Title:
Exoplanet research at the University of Bristol
Abstract:
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Sarah Casewell
Presentation type: talk
Title:
Brown dwarfs in irradiated environments
Abstract:
I will present recent results on 2 of the best known irradiated brown dwarfs in close post common envelope binary systems. These systems have orbital periods of 2 hours and contain relatively cool white dwarfs that irradiate their tidally locked brown dwarf companions. The resultant heating can cause photochemical effects as well as a day and night side that differ in temperature by as much as 500 K. I will present our recent results on these systems, and describe how similar effects may occur in exoplanetary systems.
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Heather Cegla
Presentation type: talk and poster
Title:
Spectral Line Variability in Exoplanet Host Stars: Disentangling Planetary Signatures
Abstract:
Progress in our knowledge of exoplanets heavily relies on our understanding of the host star. In particular, stellar magnetic activity plays a fundamental role not only in planet habitability, but also in accurately ascribing the planetary nature of an observed signal (activity changes the stellar line shapes, thereby introducing spurious radial velocities [RVs]). Even stars with low-level magnetic activity exhibit spectral line variability of 10s of cm/s (or more) due to stellar surface magneto-convection and p-mode oscillations. Our aim is to study the behaviour of spectral lines through the use of 3D magnetohydrodynamical simulations coupled with 1D radiative transport. We simulate a time-series of the solar surface that allows us to parameterise the granulation signal and construct Sun-as-a-star model observations (which we compare to empirical observations). These model observations reveal that several line properties correlate with the induced RVs and may be used to reduce convective noise; such noise reductions will be crucial in the confirmation of terrestrial-mass planets in the habitable zone. In addition, we quantify the variation in convective-blueshift across the limb due to the corrugated nature of granulation; ignoring this variation may affect detailed spectroscopic transit studies, such as Rossiter-McLaughlin (RM) observations. We investigate this impact on RM data using the aforementioned stellar model and SOAP-T (a software tool used for RM analysis). We present our initial results, and comment on the influence of stellar line profile shape in accurately modelling RVs.
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Bill Chaplin
Presentation type: institutional summary
Title:
Asteroseismology and Exoplanets at Birmingham
Abstract:
In this talk I will review the research ongoing at Birmingham, with a particular emphasis on the use of asteroseismology to characterize exoplanet systems.
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Katy Chubb
Presentation type: poster
Title:
Three years of Exomol: new molecular line lists for exoplanet and other hot atmospheres
Abstract:
Fundamental molecular data play a key role for spectral characterization of astrophysical objects cool enough to form molecules in their atmospheres (cool stars, extrosolar planets and planetary discs) as well as in a broad range terrestrial applications. However, at elevated temperatures, the laboratory data for a number of key species is absent, inaccurate or incomplete. The ExoMol project aim to providing comprehensive line lists for all molecules likely to be observable in exoplanet atmospheres in the foreseeable future [1]. This is a huge undertaking which will mean providing in excess of a hundred of billions of spectral lines for a large variety of molecular species [2].
The physics of molecular absorptions is complex and varies between different classes of absorbers, which are therefore divided into following topics (a) diatomic, (b) triatomics, (c) tetratomics, (d) methane and (e) larger molecules. Special techniques are being developed to treat each case. The line lists for a number of key atmospheric species currently available from ExoMol (www.exomol.com): NH3 [3], CaH, MgH, BeH [4], SiO [5], HCN/HNC [6], KCl, NaCl [7], CH4 [8], PN [9], PH3 [10], H2CO [11], AlO [12], NaH [13] ScH [14]. The line lists currently being constructed include those for SO2, SO3, AlH, C2, C3, PO, PS, PH, SH, SiH, CrH, TiH, H2S, HNO3, C2H4, CH3Cl and C2H2. We will present examples of molecular spectra computed using the ExoMol line lists.
This work is part of the ExoMol project supported by the ERC under Advanced Investigator Project 267219. We thank STFC for providing time on HPC systems Darwin and COSMOS as part of their DiRAC facility.
References [1] J. Tennyson and S.N. Yurchenko, Mon. Not. R. Astron. Soc., 425, 21 (2012). [2] J. Tennyson and S.N. Yurchenko, Exp. Astron., in press (2014). [3] S.N. Yurchenko, R.J. Barber and J. Tennyson, Mon. Not. R. Astron. Soc., 413, 1828 (2011). [4] B. Yadin et al, Mon. Not. R. Astron. Soc., 425, 34 (2012). [5] E.J. Barton, S.N. Yurchenko and J. Tennyson, Mon. Not. R. Astron. Soc., 434, 1469 (2013). [6] R.J. Barber et al, Mon. Not. R. Astron. Soc., 437, 1828 (2014). [7] E.J. Barton et al, Mon. Not. R. Astron. Soc., 442, 1821 (2014). [8] S.N. Yurchenko and J. Tennyson, Mon. Not. R. Astron. Soc., 440, 1649 (2014). [9] L. Yorke et al, Mon. Not. R. Astron. Soc., 445, 1383 (2014). [10] C. Sousa-Silva et al, Mon. Not. R. Astron. Soc., 446, 2337 (2015). [11] A.F. Al-Refaie et al, Mon. Not. R. Astron. Soc., 448, 1704 (2015). [12] A.T. Patrascu et al, Mon. Not. R. Astron. Soc., in press (2015). [13] T. Rivlin et al, Mon. Not. R. Astron. Soc., submitted. [14] L. Lodi et al, Mol. Phys., in press (2015).
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Gavin Coleman
Presentation type: talk
Title:
Forming low-mass compact planetary systems
Abstract:
The question of how low-mass compact planetary systems form from proto-planetary discs has become increasingly important with the discovery of numerous systems such as Kepler 11 and Kepler 186. We use the publicly available Mercury-6 symplectic integrator coupled with a self-consistent 1D disc model to explore numerous processes affecting planetary formation. These include N-body interactions between multiple planetary bodies, disc-induced planetary migration, planetary gas accretion and planetesimal growth, and disc dispersal through photo-evaporation. We performed numerous N-body simulations with prescriptions for the processes described above, to examine whether the oligarchic growth scenario of planetary formation can adequately form low-mass compact systems, as well as more exotic planetary systems. We will then discuss the results of these simulations before making comparisons with currently observed planetary systems to see where improvements to our model are required.
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Guy R. Davies
Presentation type: talk
Title:
Time: the final, final frontier - Ageing exoplanet host stars.
Abstract:
In an era of planetary transits and Doppler wobbles, characterising exoplanet host stars is import work. Obtaining precise and robust ages of host stars can be very challenging. Here I will present recent work determining ages of solar-type exoplanet host stars using the technique of asteroseismology. Using the frequencies of modes of stellar acoustic oscillations along with spectroscopic constraints, one can estimate stellar ages for main sequence F- and G-type stars to precisions that can reach ~10%. Not only can we determine the ages of individual stars, but asteroseismic ages may also be used to calibrate empirical ageing relations (mass-age-rotation) for much wider application.
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Brice-Olivier Demory
Presentation type: talk
Title:
Variability in the atmosphere of a super-Earth exoplanet
Abstract:
Considerable progress has been made in recent years in observations of atmospheric signatures of giant exoplanets, but processes in rocky exoplanets remain largely unknown due to major challenges in observing small planets. Numerous efforts to observe spectra of super-Earths, exoplanets with masses of 1-10 Earth masses, have thus far revealed only featureless spectra. I will present in this talk the detection of variability in the dayside thermal emission from a transiting super-Earth orbiting a nearby sun-like star. Dedicated space-based monitoring of the planet in the mid-infrared over eight eclipses revealed the thermal emission from its dayside atmosphere varying by a factor of three between 2012 and 2013. The amplitude and trend of the variability are not explained by potential influence of star spots or by local thermal or compositional changes in the atmosphere over the short span of the observations. The possibility of large scale surface activity due to strong tidal interactions possibly similar to Io, or the presence of circumstellar/circumplanetary material appear plausible. I will discuss the implications of the findings that may be relevant for all ultra-short period exoplanets.
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Rupert Dodkins
Presentation type: poster
Title:
MKIDs: next generation exoplanet detectors
Abstract:
Microwave Kinetic Inductance Detectors are a new cryogenic detector which operate from far infrared to X-rays. They can measure the energy of individual photons to within a few percent and the arrival time to a few microseconds, essentially removing the requirement for exposure times and optical filters. Their high sensitivity with essentially no read noise and simple design means they are the ideal detector for exoplanet astronomy. DARKNESS, the Dark-speckle Near-infrared Energy-resolved Superconducting Spectrophotometer, promises to revolutionise the direct imaging of extrasolar planets.
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Amanda Doyle
Presentation type: poster
Title:
The influence of stellar macroturbulence on spectral lines
Abstract:
In 1D model atmospheres, macroturbulence represents convection in stellar photospheres. Macroturbulence has the effect of broadening spectral lines, and can make it difficult to measure other broadening parameters such as rotational velocity. This poster details why it is important to measure the macroturbulence accurately, with a particular focus on depth dependence.
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Benjamin Drummond
Presentation type:
Title:
Fully Consistent Non-Equilibrium Chemistry in hot Jupiter Atmospheres
Abstract:
I will present new results from a study of non-equilibrium chemistry in exoplanet atmospheres under conditions relevant to a wide range of planetary types (hot Jupiters to ice giants). I will show that non-equilibrium chemistry can affect the temperature structure of hot Jupiter atmospheres with a large impact on the nightside (a few hundred Kelvin) but a much smaller effect on the dayside. This highlights the need to use both 1D and 3D models together, in a complimentary manner, to study these asymmetric planets. We have developed a 1D radiative-convective atmosphere model, coupling consistently hydrostatic equilibrium, radiative transfer and chemistry. I will also discuss our current developments, the implementation of our non-equilibrium chemistry code in the Met Office UM, a sophisticated general circulation model (GCM). Previous studies either assume chemical equilibrium or do not allow non-equilibrium chemistry to feedback on to the background atmosphere, and none so far have included true chemical kinetics in a 3D GCM.
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Daniel Evans
Presentation type: poster
Title:
Stellar Companions to Exoplanet Host Stars in the Southern Hemisphere
Abstract:
A new Lucky Imaging search for close stellar companions to 101 transiting exoplanet host stars in the Southern hemisphere is presented. The presence of a second star can dilute, or in some cases mimic, an exoplanet transit signature, and it is important to account for this when analysing transit photometry. Additionally, wide binaries may be involved in the migration of Hot Jupiters inwards from the ice line, as well as the creation of systems with spin-orbit misalignments. This survey aims to create a complete list of companion stars from sub-arcsecond scales out to 20 arcseconds. Two colour photometry has been used in some cases to determine the properties of the companion stars. Further observations are planned to extend two colour coverage to all stars in the sample, as well as adding a number of recently published planetary systems.
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Tom Evans
Presentation type: talk and poster
Title:
ExoMOS: a purpose-built instrument for characterising exoplanet atmospheres
Abstract:
I will present an overview of the Exoplanet Multi-Object Spectrograph (ExoMOS), an optical-IR instrument designed for exoplanet atmosphere characterisation. Our consortium, which is led by the UK with additional European collaborators, is proposing to mount ExoMOS at the Nasmyth focus of the 3.6m ESO New Technology Telescope in La Silla, with anticipated first light in 2019. ExoMOS will provide simultaneous wavelength coverage across 0.4-2.4 micron at a resolving power of R~1000 for bright V=7-12mag targets. The primary science goals are: (1) a comprehensive transmission and emission spectroscopy survey for at least 100 hot Jupiters; and (2) detailed follow-up for approximately 80 favourable super-Earths and Neptunes discovered by surveys such as NGTS and TESS. These initial science programs will run for 5 years, after which ExoMOS will continue to operate indefinitely as a community instrument, well into the era of upcoming missions such as PLATO.
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Stephen Fendyke
Presentation type: talk
Title:
UV and X-ray Photoevaporation of Circumbinary Discs
Abstract:
Understanding how protoplanetary discs evolve is a key ingredient of any predictive theory of planet formation. It is now well established that photoevaporation by the central star plays a major role in the evolution and dispersal of these planet-forming discs. Here we present the first hydrodynamic models of disc photoevaporation around binary stars. We consider both X-ray and EUV irradiation, and include a new treatment of the diffuse (recombination) field in the EUV case. Our results have important implications for disc evolution in binary systems, and the formation of circumbinary planets. Moreover, circumbinary discs do not suffer from the same degeneracies found in single-star systems, and consequently we find that studying photoevaporation in binary systems may allow us, for the first time, to determine photoevaporative mass-loss rates empirically.
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Dora Fohring
Presentation type: talk
Title:
Scintillation Noise in Exoplanet Transit Photometry
Abstract:
Transit photometry is a powerful technique which allows us to probe the orbital architecture, composition and atmospheric dynamics of transiting exoplanets. Up to date, much of the ground breaking results have come from space, although ground-based observations continue to play a significant role. Observations from the ground are limited by scintillation noise from the Earth’s atmosphere, which places a fundamental constraint on the photometric precision that can be obtained. The regimes where scintillation dominates depend on the object brightness and the turbulence profile of the atmosphere. Through atmospheric profiling using stereo-SCIDAR, we are able to accurately predict the scintillation noise on time-series photometry and model its effect on the uncertainty in the astrophysical parameters obtained. Using simulation, we predict the improvement on the astrophysical parameters when employing scintillation-correcting instruments such as the conjugate-plane photometer.
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Ryan Garland
Presentation type: poster
Title:
Modelling the Spectra of Brown Dwarfs
Abstract:
Brown dwarfs are free-floating objects with similar properties to gas giant exoplanets, such as their radius and atmospheric composition. One of the main benefits of brown dwarf research is that their free-floating nature allows a much higher signal-to-noise ratio than their exoplanet counterparts. Thus, the high resolution spectra of brown dwarfs present the perfect testing bed for (directly-imaged) exoplanetary atmospheric physics and high-temperature molecular line lists.
My thesis research is on the retrieval of atmospheric structure and composition of brown dwarfs using optimal estimation techniques. I have investigated the importance of high-temperature molecular line lists and the parameterisations of line opacity with H2-He-dominated atmospheric pressure-broadening. My findings indicate that pressure-broadening makes a large difference to the retrieved spectra when compared to ignoring pressure-broadening altogether. We therefore highly recommend using the appropriate pressure-broadening parameters for atmospheric retrievals on brown dwarfs.
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Edward Gillen
Presentation type: talk and poster
Talk title:
Constraining the early stages of stellar evolution with eclipsing binaries
Talk abstract:
There are only a handful of known low-mass, pre-main sequence eclipsing binaries (PMS EBs) with well-determined masses and radii. Detecting and characterising a sample of low-mass EBs sharing the same age and composition, yet spanning a wide range of masses, was one of the key motivations for CoRoT to observe the 3 Myr old NGC 2264 star forming region for 23 days in 2008. We identified 37 EBs among the possible cluster members and have performed an intensive program of ground-based follow-up observations to confirm their membership and determine their parameters. Furthermore, CoRoT observed the cluster again for 40 days in Dec 2011 - Jan 2012, as part of a coordinated campaign with Spitzer, Chandra, and a number of ground-based facilities including VLT/FLAMES, providing a unique simultaneous multi-band photometric and spectroscopic dataset. I will present the sample of confirmed and candidate cluster members, detailing our innovative methods to determine their fundamental parameters using Gaussian process regression, before comparing our results to different models of stellar evolution.
Poster title:
The first low-mass, pre-main sequence eclipsing binary with evidence of a circumbinary disk
Abstract:
We present a new double-lined, detached eclipsing binary, which comprises two pre-main sequence M dwarfs and shows evidence of a circumbinary disk. This unique system, which could be a precursor of the circumbinary planetary systems discovered by Kepler, enables us to test evolutionary models of low mass stars, and the interaction between a close binary and a circumbinary disk.
CoRoT223992193 was discovered by the CoRoT space mission during a continuous, 23-day observation of the NGC2264 star-forming region. Using our innovative Gaussian process regression methods, we solve the orbit and derive the fundamental parameters of both stars by modelling the CoRoT photometry together with WHT/ISIS and VLT/FLAMES spectra.
The system’s spectral energy distribution (SED) shows a mid-infrared excess that can be modelled as thermal emission from dust in the inner cavity of a circumbinary disk. Additionally, the CoRoT light curve contains large-amplitude, rapidly evolving out-of-eclipse variations, which might be due in part to occultations of the central stars by material located at the inner edge or in the central cavity of the circumbinary disk. We are now analysing the out-of-eclipse variability using a second season of coordinated CoRoT, Spitzer and CFHT/MegaCam observations.
I will present the stellar fundamental parameters and our SED modelling, before discussing our ongoing work on the origin of the out-of-eclipse variations and variations in the system’s multi-component Hα line profile.
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Maximilian Guenther
Presentation type: talk
Title:
Expected Yield of Planets and False Positives in Transit Surveys
Abstract:
It is crucial for transit surveys to ensure they find a large number of signals but also that the number of planets is not overruled by a population of false positives. In particular background eclipsing binaries (BEBs) can be very costly to follow up. To address this issue, I have developed a new program to compute the planet and false positive yield of transit surveys, specifically taking BEBs into account. In this talk, I will present my results for the upcoming NGTS and TESS transit search missions.
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Aimée Hall
Presentation type: talk and poster
Title:
Early results from reprocessing of the SuperWASP survey
Abstract:
SuperWASP is already a highly successful ground-based exoplanet transit survey, however, its complex instrumental systematics so far have set a limit on the minimum noise level achievable. Reducing the noise contribution would allow smaller planets to be found in the SuperWASP data.
By quantifying and accounting for these systematics up front, rather than in the post-processing stage, the photometric noise can be significantly reduced. I present and discuss the properties of the resulting lowered rms noise and its application to SuperWASP searches for exoplanet transits.
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Cassandra Hall
Presentation type: poster
Title:
Observational Signatures of Self Gravitating Protostellar Discs
Abstract:
Recent ALMA observations of the disc surrounding the T Tauri star HD142527 have revealed spiral structure in 12 CO J=2-1 emission that extends out as far as 600 AU. We use Monte-Carlo radiative line transfer with an analytic, self-consistent, self-gravitating disc calculations to examine if these spiral structures could be self-gravitating spiral waves. We generate synthetic images using the CASA package, to establish if the spiral amplitudes are large enough to produce features that would be detectable by ALMA.
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Tom Hands
Presentation type: talk
Title:
There Might Be Giants
Abstract:
The limited completeness of the Kepler sample for planets with orbital periods greater than ~1yr leaves open the possibility that some exoplanetary systems may host as-yet undetected extra planets. Should such planets exist, their dynamical interactions with the inner planets may prove vital in sculpting the final orbital configurations of these systems. Using an N-body code with additional forces to emulate the effects of a protoplanetary disc, we perform simulations of the migration of systems of super-Earth mass planets with unseen giant companions. The systems formed in these simulations are analogous to Kepler-11 or Kepler-32, containing 4-6 inner planets, with giant companions which are unlikely to have been detected by Kepler. We use the results of these simulations to explore the effect that unseen giant companions would have on mean-motion resonances between the innermost planets in such systems.
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Carole Haswell
Presentation type: institutional summary
Title:
Exoplanet Research at the OU
Abstract:
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Kirstin Hay
Presentation type: poster
Title:
Is the highly eccentric orbit of WASP-118b misaligned?
Abstract:
We present the discovery of WASP-118b, which has one of the most eccentric orbits among the WASP hot Jupiters. The high eccentricity of the orbit suggests that it might be in the final stages of tidal circularisation following high-eccentricity migration. Two radial-velocity (RV) measurements obtained during transit suggest a near polar orbit, which combined with the near 4-day orbital period and the high eccentricity point strongly towards secular dynamics rather than disc migration as the main driver of its orbital evolution.
WASP-118 will be on silicon in an upcoming field of the Kepler K2 mission. The system will thus be a key target for the Rossiter-McLaughlin effect and high-precision photometric observations in the near future.
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Raphaelle Haywood
Presentation type:
Title:
Exploring the Sun’s activity-driven radial-velocity variations to improve exoplanet detections
Abstract:
The Sun is the only star whose surface can be directly resolved, and therefore constitutes an excellent test case to explore the physical origin of stellar radial-velocity (RV) variability. We recently obtained HARPS observations of sunlight reflected from the bright asteroid Vesta, from which we deduced the Sun’s activity-driven RV variations. In parallel, the HMI instrument aboard the Solar Dynamics Observatory provided us with simultaneous high spatial resolution magnetograms, dopplergrams, and continuum images of the Sun. These allowed us to determine the RV contributions of individual surface structures such as spots, faculae/plage, and surface granulation, and to look for new activity proxies. We find that the activity-driven RV variations of the Sun are strongly correlated with its full-disc magnetic flux, and may be a useful proxy for activity-related RV noise in exoplanet searches.
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Christina Hedges
Presentation type: poster
Title:
The Importance of Accurate Molecular Spectroscopy for Characterising Exoplanetary Atmospheres
Abstract:
Observations of hot Jupiters over the past few years have opened up the field of study of exoplanet atmospheres. By taking spectroscopic observations it is possible to determine elemental and molecular abundances within the atmospheres of exoplanets with statistical significance. These data can be used to further investigate temperature inversions and the presence of clouds in other planets. With transition line-list data being updated for many of the relevant molecules, at much higher temperatures than was previously available, it is now possible to scrutinise the transition features of these molecules and the application of high temperature line-lists in atmospheric studies. Molecular transition features vary under different temperature and pressure regimes and this variance affects the detection of atmospheric lines in given bandpasses. In this work we demonstrate the importance of accurate line-lists and broadening parameters for calculating reliable molecular cross sections and discuss their implications for abundance determination. We present an investigation into the relevant molecules for atmospheric studies and how their absorption features correlate with the bandpasses of instruments involved in exoplanet spectroscopy. We identify optimal bandpasses on current and future instruments available for atmospheric characterisation of exoplanets. We discuss the intrinsic variation of these molecular features with temperature.
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Coel Hellier
Presentation type: institutional summary
Title:
Exoplanet research at Keele University
Abstract:
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Christiane Helling
Presentation type: institutional summary
Title:
Exoplanetary research in St Andrews
Abstract:
A.C. Cameron, M. Dominik, J. Greaves, Ch. Helling, K.D. Horne, P. Woitke et al.
St Andrews exoplanetary research interest ranges from exoplanet detection, multi-wavelength analysis of protoplanetary disks, and the studies of planetary atmospheres.
Planet searches are performed by means of microlensing searches with robotic telescopes, the WASP project, and the follow-up with Harps North and the local JGT. Protoplanetary disk research combines multi-wavelength detection with extensive disk modelling by ProDiMo. Our planetary atmosphere research includes the study of turbulence and cloud formation, and the electrification of planetary atmospheres through e.g. cosmic rays and lighting.
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Gabriella Hodosán
Presentation type: talk
Title:
Lightning on exoplanets and brown dwarfs: What can we learn from Solar System analogies?
Abstract:
Lightning has an important role in nature. It has been shown that in certain conditions electrostatic discharges may result in the production of pre-biotic molecules important for the formation of life. These conditions may appear on extrasolar objects (exoplanets and brown dwarfs (BDs)). Also, the presence of lightning suggests convection (moist or dust particle) and carries information on the atmosphere and cloud formation of the investigated planet.
Large-scale electrostatic discharges have been observed in the Solar System (directly on Earth, Jupiter and Saturn, indirectly on Uranus, Neptune and Venus). The presence of clouds in the atmosphere is a key feature for lightning formation. Clouds also form in atmospheres of extrasolar planets and brown dwarfs, though with different material compositions. Large-scale discharge processes, like lightning, can also occur in such mineral cloud.
We use lightning detection data from Earth, Jupiter and Saturn to study potential discharge characteristics on extrasolar objects. We focus on lightning climatology studies, which allows exploration of the global variations in lightning occurrence. Guided by these data, we estimate the energy dissipated globally by lightning discharges in an exoplanet or BD atmosphere
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Patrick Irwin
Presentation type: institutional summary
Title: Exoplanet research at the University of Oxford
Abstract:
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Hugh Jones
Presentation type: institutional summary
Title:
Exoplanet research at the University of Hertfordshire
Abstract:
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Tiffany Kataria
Presentation type: talk
Title:
The atmospheric circulation of hot Jupiters in the WASP sample
Abstract:
As observations of exoplanet atmospheres have grown in number and complexity, spanning a larger wavelength range at ever-higher spectral resolution, circulation models continue to be a vital component in interpreting these observations. Here I will present three-dimensional (3D) atmospheric circulation models of two hot Jupiters in the Wide Angle Search for Planets (WASP) sample that have been heavily characterized by ground- and space-based observations. First, I will present preliminary results from an analysis of WASP-17b, a 0.5 Jupiter-mass, 2 Jupiter-radius planet that is part of our research group’s eight-planet Hubble Space Telescope atmospheric survey of transiting hot Jupiters. The transmission spectra of WASP-17b appear consistent with a planet that has a small amount of haze or clouds, and I demonstrate the feasibility of such a scenario. Next, I will present results from a detailed study of the ultra-short period (19.5-hour) hot Jupiter WASP-43b, a 2 Jupiter-mass, 1 Jupiter-radius planet that orbits a K star. I will compare these models to an observational dataset utilizing the Wide Field Camera 3 aboard HST to collect spectrophotometric phase curve measurements of WASP-43b from 1.12-1.65 microns. My results show the data are most consistent with an atmosphere slightly enhanced in metallicity; the 5x solar lightcurve provides a good match to the data, with a phase offset of the lightcurve flux peak and planet/star flux ratio similar to observations. While the model nightside appears to be brighter than the observations, our 5x solar model provides an excellent match to the WFC3 dayside emission spectrum. This is a major success as the result is natural outcome of the 3D dynamics, with no model tuning. In sum, these results demonstrate that 3D circulation models can provide tremendous insights in interpreting exoplanet atmospheric observations, even at high spectral resolution, and highlight the potential for future observations using HST, JWST and other next-generation telescopes to characterize exoplanet atmospheres from WASP and other future surveys.
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Grant Kennedy
Presentation type: talk
Title:
A wider view of planetary system alignment
Abstract:
The orbits of many planets are seen to be misaligned with the spin of their host stars, and the known circumbinary planets show a high degree of coplanarity with their binary host orbits. The origins of planetary system (mis)alignment are poorly constrained, but resolved images of Kuiper belt analogues provide one path towards a better understanding. I will summarise my work on alignment of stars, planets, binaries, and discs in a handful of systems, and discuss the prospects for testing various planet misalignment scenarios.
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Eamonn Kerins
Presentation type: institutional summary
Title:
Exoplanet research at Manchester
Abstract:
I will overview recent and ongoing exoplanet research at Manchester, including our involvement in the preparation of an exoplanet microlesing additional science survey for Euclid and the search for exoplanets around pulsars.
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James Kirk
Presentation type: poster
Title:
Transmission Photometry with ULTRACAM
Abstract:
Transiting planets provide the greatest opportunity for characterisation using techniques such as transmission spectroscopy to infer information about their atmospheres. A ground based approach uses simultaneous photometric measurements of a transiting planet in different bands to study how the planetary radius changes with wavelength. I will present the application of this technique, using ULTRACAM, to WASP-52b, an inflated hot jupiter expected to have a large atmospheric scale height making it a good candidate for such transmission photometry work.
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Graham Lee
Presentation type: talk
Title:
Nucleation and Cloud Formation in HD 189733b
Abstract:
Context. Recent observations of HD 189733b suggest that the exoplanet has a cloud/haze component in its atmosphere. The presence of cloud/haze has an effect on the local thermodynamic and chemical properties of the atmosphere. Unlike Earth, where cloud condensation nuclei are provided by the upward motion of sand or ash, in hot Jupiters these condensation seeds form from the gas phase. The rate at which these seeds form is determined by the local thermodynamic conditions and the chemical composition of the local gas phase. Since hot Jupiters have different thermodynamic conditions from their dayside to nightside faces we expect them to exhibit locally and globally different cloud structures. This has implications on interpreting observations of the atmosphere which probe different atmospheric regions and depth.
Aims. Inspired by mineral cloud modelling efforts for Brown Dwarf atmospheres, we present spatially varying kinetic cloud model structures for HD 189733b.
Methods. We apply density functional theory (B3LYP, 6-311G(d)) to derive updated thermodynamical data for (TiO2)N-clusters as input for our TiO2 seed formation model. We switch to a SiO nucleation model in order to assess which species nucleates most efficiently. We follow a 2-model approach approach using results from a 3D global radiation-hydrodynamic atmospheric simulation of HD 189773b (Dobbs-Dixon & Agol 2014) as input for our kinetic cloud formation model.
Results. We present updated nucleation rates for TiO2 and SiO, and find TiO2 remains the most suitable nucleation species (Lee et al. 2015) We present cloud maps for HD 189733b based on a kinetic cloud formation model, and we demonstrate how the cloud structure changes locally and globally tracing the local thermodynamics of the atmosphere The calculated cloud properties show variations in composition, size and number density of cloud particles which are strongest between the dayside and nightside. The cloud particles scattering properties suggest that they would sparkle/reflect a midnight blue colour at optical wavelengths.
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Stefan Lines
Presentation type: talk
Title:
Two’s a crowd: the difficulties of circumbinary planet formation
Abstract:
Recently discovered circumbinary planets provide a stringent test for planet formation models by requiring planets to form in a particularly extreme, dynamically hot environment. Gravitational perturbations on the planetesimals from the binary stars drive up the eccentricities and impact velocities of the planetesimals, increasing their tendency to undergo disruptive collisions during the core accretion phase of planet formation. The gaseous component of the accretion disk is similarly affected. The gravitational interaction between the gas disk and the stellar binary can lead to a highly eccentric, precessing disk. A combination of planetesimals and the gas disk results in a number of adverse effects which further increases the likelihood of erosive, growth-inhibiting collisions between circumbinary planetesimals. Despite the apparent difficulty in growing terrestrial planets and giant planet cores in such systems, Kepler has discovered a number of planets in short-period circumbinary, P-type orbits. In our work we address how these planets could have formed by conducting N-body and hydrodynamic fluid simulations of these hostile circumbinary disks.
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Emma Longstaff
Presentation type: poster
Title:
Irradiated Brown Dwarfs
Abstract:
Detached white dwarf (WD) + brown dwarf (BD) binary systems are rare and there are only a handful of confirmed examples to date. BDs bridge the formation gap between stars and planets, although they do not burn hydrogen in their core; they do, however, have a short period of deuterium burning during the early stages of their formation. Close brown dwarf companions to main sequence stars are rare (e.g. Wasp-30B), and directly detecting them is challenging due to the brightness of the host star. Brown dwarf companions to white dwarfs, however, are easier to detect as the contrast is much higher with the brown dwarf dominating the spectral energy distribution longwards of 1.65μm, where the white dwarf is faint. These systems also offer fascinating insights into an extreme type of binary formation and evolution. This poster presents Xshooter observations of two WD+BD binary systems: WD0137-349 and NLTT5306. Both systems are short period, detached, non-eclipsing binaries where the tidally-locked BD companion is being irradiated by the WD. It is thought that both WD0137-349 and NLTT5306 have survived common envelope evolution leading to system periods of 116 min and 101.88 min respectively. The main differences between the binaries are that NLTT5306 has a much cooler WD at ~7700 K compared to WD0137-349 at ~16,500 K and the Hα emission line is in phase with the absorption in NLTT5306, whereas it is in anti-phase in WD0137-349 (Steele et. al. 2012). I display radial velocity curves, trailed spectra and show how the near-infrared emission varies with orbital phase of both systems. I intend to follow this up with further analysis of the near-infrared spectrum to investigate the variability in the atmospheres of BDs as this could be a useful tool for modelling the atmospheres of hot-jupiter exoplanets.
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Eric D. Lopez
Presentation type: talk
Title:
The Evolution and Compositions of Sub-Neptunes and Super-Earths
Abstract:
NASA's Kepler mission has uncovered a large new population of super-Earth and sub-Neptune sized planets. Understanding these planets poses a fundamental test for models of planet formation and evolution. My work focuses on using models of planet structure, thermal evolution, and atmospheric evaporation to examine the possible origins and compositions of these planets. I am especially interested in the transition between rocky super-Earths and gaseous sub-Neptunes, the possible compositions of the sub-Neptunes, and the role that atmospheric photo-evaporation plays in sculpting these populations.
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Tom Louden
Presentation type: talk
Title:
High resolution transmission spectroscopy of HD 189733b
Abstract:
We present a high resolution transmission spectrum of the hot jupiter HD 189733 b recovered from archival HARPS data. We detect sodium absorption with comparable strength to previous studies and use the exceptional resolution of HARPS to study the profile of the absorption line. Our study demonstrates that HARPS can be used to study the composition of exoplanetary atmospheres.
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Deepak Mahtani
Presentation type: talk
Title:
Semi-synthetic secondary eclipse lightcurves of hot Jupiter exoplanets
Abstract:
Secondary eclipse observations allow the characterisation of the dayside of hot Jupiter exoplanet atmospheres. The standard, state of the art way of getting these observations is by using IRAC on the Spitzer Space Telescope. This instrument was not designed to reach the precision required to conduct these observations. However, it is possible to push IRAC to detect the secondary eclipse. It has been used for nearly 10 year to observe secondary eclipses of a handful of exoplanets. The data are strongly affected by systematic errors which can limit the accuracy that we can measure the depth of the eclipse, as well as other parameters that can be derived from the lightcurve. In this talk I discuss the way that the WASP group analyses these data and describe a method of signal injection that can help in determining more realistic error bars on the time of mid eclipse and the eclipse depth. The two are fundamental parameters that come out of these observations. I also describe the work I would like to conduct as a postdoctoral research assistant once I have completed my PhD.
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Pierre Maxted
Presentation type: poster
Title:
Bayesian mass and age estimates for transiting extrasolar planet host stars
Abstract:
We describe a method to derive the probability distribution for the mass and age of a transiting extrasolar planet host star from its observed properties. We use this method to show that the gyrochronological ages of some transiting exoplanet host stars are significantly less than their isochronal ages.
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James McCormac
Presentation type: poster
Title:
The Next Generation Transit Survey
Abstract:
The Next Generation Transit Survey (NGTS) is a new wide-field transiting exoplanet survey aimed at discovering Neptune and super-Earth size exoplanets around bright ($V<13$) stars in the solar neighbourhood. NGTS is currently being commissioned at ESO's Paranal observatory, Chile and consists of an array of $12$ robotically operated telescopes observing in the $600-900$ nm band; hence maximising the sensitivity to small but bright K and M dwarf stars. Observing K and early M type stars theoretically permits the detection of smaller transiting exoplanets as the radius of the host star is reduced compared to solar-type stars. Simulations have shown that NGTS will survey more than five times the number of stars with $V<13$ than Kepler and will therefore provide the brightest targets for characterisation with existing and future instrumentation (VLT, E-ELT and JWST). Many recent discoveries of planetary systems harbouring Neptune-mass planets and super-Earths clearly indicate that low-mass planets around solar-type stars are very common. Paranal boasts exceptional photometric conditions and a low atmospheric water vapour content for a significant fraction of the year, which is essential for NGTS to perform photometry at the required millimagnitude level or better. In 2009/10, a prototype system for NGTS was tested on La Palma, and in 2013 the first NGTS unit was tested in Geneva, both proving that the system can meet our goals of essentially white noise limited photometry of bright stars. Several improvements in the design of NGTS resulted from the prototyping phase (e.g. requirements for baffling and autoguiding) and have now been integrated into the facility at the ground level. The NGTS project is made up of partners from the University of Warwick, University of Leicester, University of Cambridge, Queen's University Belfast, Observatoire de Geneve and DLR Berlin. NGTS builds on the experience of the SuperWASP project, which, for many years, has lead the ground-based detection of transiting exoplanets.
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Will McLean
Presentation type: talk and poster
Title:
Spectropolarimetry as a tool for the characterisation of exoplanets
Abstract:
Traditionally, exoplanet atmospheres are characterised through the study of light from the parent star, when passing through the planet’s atmosphere. The planet is observed when it is transiting the star, and when the star is eclipsing it, allowing us to disentangle the spectrum of the planet from that of the host star. Spectropolarimetry is a complementary method, and yields additional diagnostic content to that of standard intensity measurements. Integrated over the disk of the star, stellar light is generally unpolarised, so any polarised signature from a system containing an exoplanet is due to the light scattered by the atmosphere, and/or surface of the planet. The application of spectropolarimetry to exoplanet science is at the limit of current instrumentation, but in the meantime the planets of our solar system provide an excellent opportunity to take benchmark spectra, with which future observations of exoplanets can be compared with. I will outline the advantages offered by spectropolarimetry, then present some recent observations of various objects of our solar system, and discuss their relevance to exoplanet science.
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Annelies Mortier
Presentation type: talk
Title:
Earth-like exoplanet signals hidden by stellar activity
Abstract:
Discovering Earth-like exoplanets using the radial velocity (RV) technique is being challenged by stellar activity. Only by understanding the variable signals imposed by the star itself will we be able to find the underlying planetary signals. Activity indicators, such as the FWHM of the spectral lines and the Ca II H&K emission, are already being used to understand the stellar variations. However, the high-resolution spectra that we have from the RV searches contain much more information. In this talk I will explain about our work on extracting precise RV's simultaneously with information on the stellar magnetic field strength. We apply this new technique to the high-resolution spectra timeseries taken with HARPS-N in order to discover Eqrth-like planets around solar-type stars.
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Alexander Mustill
Presentation type: talk
Title:
The destruction of inner planetary systems during the high-eccentricity migration of gas giants
Abstract:
Small close-in planets have not been observed in systems containing hot Jupiters, despite these small planets being very common in systems that do not contain hot Jupiters. We propose that the lack of such close companions can help discriminate between mechanisms for the migration of hot Jupiters. Possible migration channels are smooth migration through a protoplanetary disc, and tidal circularisation of highly-eccentric planets. We focus on the second mechanism, and conduct N-body integrations of giant planets on high-eccentricity orbits interacting with systems of small inner planets at around 0.1au. When the pericentre of the eccentric giant is small enough to allow tidal circularisation (and hence formation of a hot Jupiter), we find that within 10^6 yr, strong planet--planet interactions have either caused the ejection of the giant or, more commonly, the destruction of all the inner planets by collision with the giant or the star. In the latter case, most giant planets retain the small pericentres required to circularise to a hot Jupiter orbit; we do also find that some giants are stranded in a region of moderately-high eccentricity that is hard to populate through scattering from low eccentricities, or through tidal circularisation. Since previous studies have found that migration of hot Jupiters through a protoplanetary disc does not completely suppress the formation of low-mass planets outside the hot Jupiter's orbit, we consider that our work supports the idea that the high-eccentricity migration pathway dominates the hot Jupiter population.
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Matthew Mutter
Presentation type: talk
Title:
The Effects of Disc Self-Gravity on Circumbinary Disc Evolution
Abstract:
We use 2D hydrodynamical simulations in FARGO to investigate the role of self-gravity in circumbinary discs. Presented here are results of disc evolution and planetary migration using the Kepler-16 system as a case study. The aim of this study is to investigate the role of disc mass and self-gravity, on the dynamics and evolution of the disc and embedded planets. The outcome of these simulations show that disc mass can have a noticeable impact on the inner-disc region of these systems, where most of the current circumbinary planets have been discovered. Further features are observed in the heavier class of discs which have interesting effects on the disc structure and consequences for planetary migration. The role of self-gravity poses interesting questions for the evolution of discs and planets hosted by these systems.
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Richard Nelson
Presentation type: institutional summary
Title:
Exoplanets research at QMUL
Abstract:
The planet formation and dynamics group at QMUL undertakes research that aims to shed light on the origins and dynamical evolution of planetary systems, the dynamics of planetary atmospheres, and includes a successful programme of exoplanet discovery using radial velocity surveys. I will provide an overview of these activities, present specific highlights, and discuss future plans.
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Marion Neveu-VanMalle
Presentation type: poster
Title:
Two hot Jupiters from WASP with big brothers
Abstract:
In the swarm of multiple extrasolar planetary systems, hot Jupiters have for a long time been thought to be "only children". While recent studies demonstrated that many of them have distant companions (e.g. Knutson et al. 2014), only a handful were found to have "siblings" at moderate separations, with a full orbital period observed. Resulting from a long-term radial velocity follow-up of WASP planets with the spectrograph CORALIE, I will present two "big brothers" of hot Jupiters located at ~1 au from their parent star.
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Nikolay Nikolov
Presentation type: talk
Title:
HST Transmission Spectral Survey: A rather clear atmosphere of WASP-17b
Abstract:
Over the past decade, observations of transits have revolutionised our understanding of exoplanet atmospheres thanks in large part to spectroscopy with the Hubble and Spitzer Space Telescopes. I will present recent results for WASP17b part of a Large HST optical and near-IR spectral survey (D. Sing, PI) of eight hot Jupiters spanning a wide range of physical properties. Together with previous HST observations, this program is showing scattering by aerosols and absorption from water and alkali metals.
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Thomas North
Presentation type: talk
Title:
Prospects for detecting planets around red-giant stars
Abstract:
The Kepler mission has provided key insight into the distribution and population of planets around Sun-like stars. The story for more evolved stars is quite different, with a limited number of detections or characterisations. Here, we comment on the prospects for increasing the haul of planets around red-giant stars using Kepler and K2 data. Red-giants are interesting targets for a variety of reasons, not the least of which is that their large-amplitude oscillations mean they can be readily characterised.
We validate a simple, physically motivated model to quantify the noise properties of red-giant stars, and then use this model to make transit signal-to-noise predictions for a 13,000-strong cohort of Kepler stars that have already been identified as red giants. We discuss predictions of the fraction of red-giant targets that might have detectable planets, subject to different assumptions for the underlying planet population.
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Hugh Osborn
Presentation type: talk
Title:
New Discoveries from the WASP Archive
Abstract:
With 10 years of photometric data, the Wide Angle Search for Planets has detected well over 100 transiting Hot Jupiters. However, other interesting discoveries also lurk in the archives. This talk will cover a search for an average secondary eclipse of WASP Hot Jupiters, the potential for single transit detections with Stare data and a survey of young stars for planets, binaries & exorings.
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James Osborn
Presentation type: talk
Title:
Scintillation noise on Large and Extremely Large telescopes
Abstract:
The effect of scintillation on astronomical observations for small telescopes is well documented and can be a dominant source of noise for ground-based extrasolar planet transit photometry. However, the effect for larger apertures is less well known. In the era of large 8-10 m class telescopes and the next generation of Extremely Large Telescopes under construction it is important to quantify expected noise sources for photometric observations with the application of, for example, extrasolar planetary transit characterisation and spectroscopy. I will describe how the scintillation noise is modified for large apertures and provide examples of expected noise levels. I will also briefly describe a scintillation correction method applicable to these large telescopes.
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Hannu Parviainen
Presentation type: talk
Title:
Search for secondary eclipses in Kepler light curves
Abstract:
Detection and characterisation of weak periodic signals from noisy time series is a common problem in many different fields of astrophysics. Here I detail one approach for testing whether a signal with roughly known characteristics exists in the data, using a search of secondary eclipses from Kepler-observed photometric time series as an example. The method is based on Bayesian model selection and uses Gaussian processes to model the stochastic variability in the data in non-parametric fashion.
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Tim Pearce
Presentation type: talk and poster
Title:
The orbits and dynamics of eccentric, long-period companions
Abstract:
I work on two questions relating to eccentric, long-period companions. Firstly, what constraints can imaging place on their orbits? And secondly, how do they dynamically interact with other bodies in the system? The first question arises because we never have enough information to uniquely solve the orbit of a long-period companion. It will only cover a fraction of its orbit between imaging epochs, and orbital curvature is often undetectable. We know just four coordinates (the instantaneous sky-plane position and velocity), short of the six required for a unique orbital solution. Typically, probability distributions of possible orbits are generated by Monte Carlo (MCMC) analysis. I suggest alternative methods to characterise possible orbits, which compliment MCMC and have several advantages over the latter; they are prior-independent, probe the full region of parameter space, readily show degeneracies between orbital elements and may be quickly applied without costly numerical analyses.
The second question arises because several long-period companions have been observed in systems which also harbour debris discs. Furthermore, an unusually shaped disc could hint at the presence of an eccentric companion, even if the companion itself is unobservable. I investigate the interaction between an eccentric planet and a debris disc, considering a broad region of parameter space. I produce general, quantitative predictions which predict the outcome of this interaction, and can be used to characterize unseen companions using observed debris features.
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Saavidra Perera
Presentation type: poster
Title:
SCIDAR Scintillation Profiling and Exoplanet Transit Observations at Paranal
Abstract:
Scintillation describes the apparent brightness fluctuations of a light source caused by the atmosphere. This can be problematic for transit photometry when trying to detect small light curve variations of less than 1%. For bright targets this effect can be the dominant noise source, limiting the detection capabilities of ground based telescopes.
SCIDAR (SCIntillation Detection And Ranging) employs triangulation techniques to profile the atmospheric turbulence above the observatory from the scintillation intensity patterns for double stars with known separation.
From Autumn 2015 a SCIDAR will be in operation on one of the auxiliary telescopes at ESO's VLT in Paranal. This will provide high resolution turbulence profiles and scintillation estimates that can be used to characterise scintillation noise for high-precision photometric observations at the VLT and, for example, the nearby Next-Generation Transit Survey.
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Eva Plávalová
Presentation type: talk and poster
Title:
Do we need a system of classification for extrasolar planets?
Abstract:
Spectral classification of stars is now common and widely used. Only a few people know that its evolution into today's form has taken a matter of decades and that in its infancy was the subject of taunts. This year is the 20th anniversary of the discovery of the first extrasolar planet 51Peg b. Almost two thousand planets and thousands of planet-candidates have been discovered since then. Isn't it high time to start talking about a system of classification? Every day new planet-candidates are being discovered and with the volume of planets expected to dramatically accelerate, without a good system of classification in place, the backlog of planets waiting to be analysed would slow down research. We can discuss how this classification (taxonomy) should look like and be presented according to the existing system of classification published by Plávalová (2012). This classification uses four main parameters which cover the mass, semi-major axis, temperature, eccentricity, plus one optional parameter if known.
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Benjamin Pope
Presentation type: talk
Title:
The Palomar Kernel Phase Experiment
Abstract:
At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment and shape of the telescope optics. These errors can be corrected physically, with active and adaptive optics, and in post-processing of the resulting image. A recently-developed adaptive optics post-processing technique, called kernel phase interferometry, uses linear combinations of phases that are self-calibrating with respect to small errors, with the goal of constructing observables that are robust against the residual optical aberrations in otherwise well-corrected imaging systems. This method has not previously been used to perform astronomical observations from the ground. Here we present a direct comparison between kernel phase and the more established competitor, non-redundant masking, where we resolve the alpha Ophiuchi binary system near periastron, using the Palomar 200-Inch Telescope. This is the first case in which kernel phase has been used to resolve a system close to the diffraction limit with ground-based extreme adaptive optics observations. Excellent agreement between astrometric quantities is found between both methods, demonstrating the viability of kernel phase as an alternative to conventional non-redundant masking.
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Didier Queloz
Presentation type: institutional summary
Title:
Planet detection and characterisation
Abstract:
An outlook of the exoplanet research activities of the Astrophysics group of the Cavendish Lab will be presented.
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Ken Rice
Presentation type: poster
Title:
Disc fragmentation rarely forms planetary-mass bodies
Abstract:
Planet formation is thought to primarily occur via core accretion, but it has been suggested that some planets may form via direct gravitational collapse. It is now clear, however, that this process probably does not occur in the inner parts of protostellar discs, where the gravitational instability is likely too weak to drive disc fragmentation. Beyond 50AU, however, the conditions are suitable for fragmentation, and it has been suggested that this process may explain some of the recently observed directly imaged planets and that - in some cases - planets that form at large radii may spiral into the inner disc. We use population synthesis modelling and dynamical evolution models to consider how a population of planets at large radii may evolve. Our results indicate that it is unlikely that there is a large population of planetary mass at radii beyond 50AU and, hence, that disc fragmentation rarely forms such objects.
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Paul B Rimmer
Presentation type: talk
Title:
A Chemical Kinetics Network for Lightning on Planetary and Exoplanetary Atmospheres
Abstract:
Lightning occurs on the majority of the planets in our solar system and electric discharges have been shown to produce rich prebiotic chemistry, depending on the initial atmospheric composition. It is interesting to explore this dependence. I present an ion-neutral chemical network valid for both oxygen-rich and hydrogen-rich atmospheres at temperatures ranging from 100 K to 30000 K, which includes complex organic chemistry through the formation of glycine. This network is applied to an atmospheric model that accounts for convection, UV and X-ray photochemistry and cosmic ray chemistry. I compare this model to standard atmospheric chemical models of Earth, Jupiter and HD189733b.
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Marco Rocchetto
Presentation type: talk
Title:
The frequency and infrared brightness of circumstellar discs at white dwarfs
Abstract:
In the last decade, it has become clear that planetary systems around Sun-like and intermediate-mass stars survive, at least in part, the post-main sequence phases of their hosts. Metal-enriched white dwarf stars commonly exhibit closely orbiting dust and gas discs, resulting from the tidal disruption of rocky minor planets. The debris-polluted atmospheres of these stars are a unique and powerful laboratory to infer the bulk composition of terrestrial exoplanets, via their tidally destroyed and accreted fragments or building blocks.
While a fraction of metal-polluted white dwarfs also show significant infrared excess from an opaque disc of warm dust, the true disc frequency still suffers from significant observational biases. I will present the results of a double-blind Spitzer/HST survey that has unambiguously determined the fraction of detectable planetary debris at relaltively young white dwarfs. Furthermore, I will show the distribution tau=Lir/L strongly indicates an undetected population of circumstellar disks, and suppors the accretion of planetary debris for all polluted white dwarfs.
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Joey Rodriguez
Presentation type: talk and poster
Talk title:
The KELT Exoplanet Survey
Talk abstract:
In recent years, the exoplanet field has shifted from a goal pure discovery to a combination of discovery and characterization, with atmospheric characterization being the most exciting. Unfortunately, a large portion of the discovered extra-solar planets orbit stars that are too faint to permit atmospheric characterization. The Kilodegree Extremely Little Telescope (KELT) project is survey to detect transiting extrasolar planets around bright stars (8 < V < 11). Currently, KELT has discovered 13 planets transiting stars brighter than V = 11, with 5 of them already in press. I will present a few of these bright transiting planets and their value for characterization, and discuss the role of KELT in the field of exoplanet discovery.
Poster title:
Target Selection for the TESS Survey
Poster abstract:
The goal of the TESS mission is to discover small, rocky planets transiting bright stars. Because the mission will be bandwidth-limited, we must create a pre-launch catalog of target stars to observe. We have constructed a compiled catalog of stars from which to select TESS targets. The catalog contains all dwarf stars in the sky with spectral types F5 and later, and I < 12, along with selected sets of fainter M stars. Provisions are being made to augment the target list with stars that fall outside the nominal spectral type and magnitude limits, and to permit dynamic updating of the catalog to accommodate new survey data being released (e.g. GAIA).
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Tamara Rogers
Presentation type: institutional summary
Title:
Exoplanet research at Newcastle University
Abstract:
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Giovanni Rosotti
Presentation type: talk
Title:
The evolution of transition discs
Abstract:
Transition discs are proto-planetary discs which show evidence for an inner hole and are interpreted as discs caught in the final act of dispersal. Photo-evaporation and planet formation have both been proposed as mechanisms responsible for their creation. I have studied the combined effect of the two processes, finding that they can have a significant interplay. I will show results from a suite of 2d simulations of protoplanetary discs undergoing X-ray photoevaporation with an embedded giant planet. The formation of a giant planet can trigger the dispersal of the inner disc by photo-evaporation. I have significantly expanded the parameter space investigated in a previous work. In addition, while before the simulations were run only up to hole opening, the updated model includes thermal sweeping, needed for studying the complete dispersal of the disc. I will show how thermal sweeping, depending on the parameters, is not effective enough to destroy the outer disc, leaving many transition discs (~60-70%) in a relatively long lived phase with a gas free hole. I will discuss what this means for transition disc evolution, possibly implying that the transition disc phase could be (at least for some discs) only a transient phase.
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Pamela Rowden
Presentation type: talk
Title:
False positives and shallow eclipsing binaries
Abstract:
We are investigating the numbers and nature of possible false positive signatures arising from shallow eclipsing binaries and from blends, with specific reference to the upcoming PLATO 2.0 mission. We will demonstrate the position of different classes of binary in orbital period/maximum eclipse depth space, and give a sense of a “typical” system that may produce a false positive signature.
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Clara Sousa Silva
Presentation type: talk
Title:
EduTwinkle
Abstract:
Twinkle is a space mission which will characterise exoplanet atmospheres and it will go into low earth orbit between 2018 and 2019. It is the first space mission with a dedicated, inclusive, educational program to engage students from primary school age all the way to graduate level. Twinkle’s educational program, called EduTwinkle, will be a collection of projects aimed at all school ages which will begin this summer and continue on until, during and after Twinkle’s launch into space. There are quite a few EduTwinkle projects in the pipeline, starting with a targeted program for primary schools called Twinkle’s Little Stars, through GCSE level all the way to sixth form. The activities will range from engineering, programming and robotics challenges, through chemistry and astrobiology, all the way to science communication and the ethics of space exploration.
EduTwinkle has three main goals: To foster a productive relationship between space exploration and British schools, inspiring children and promoting science. To increase higher education access to Stem careers, particularly by focusing on improving attainment and aspiration for under-represented groups. Finally, to increase girls uptake in STEM subjects at A-level and HE, by dispelling harmful gender stereotypes and publicising the multidisciplinary nature of modern science.
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Jessica Spake
Presentation type: talk and poster
Title:
WASP-135b and spin-orbit interactions in extreme systems
Abstract:
To fully understand the formation and evolution of hot Jupiter systems, the possible effects of spin-orbit interactions need to be quantified. I will be presenting one of the latest fruits from the remarkably successful SuperWASP survey. WASP-135b is a newly confirmed hot giant planet, approximately twice as massive as Jupiter and with an orbital period of just 1.4 days, making it one of the most extreme exoplanets yet discovered. Large discrepancies between gyrochronological and isochronal age estimates suggest that it may have transferred angular momentum to its G5V host star, leading to an increase in the expected stellar spin rate.
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Daniel Staab
Presentation type: talk
Title:
Absorbing gas around a bright, mature F-star
Abstract:
One of the most dramatic early findings in the exoplanet field was the discovery of an extensive exosphere surrounding HD 209458 b, which obscured ~10% of the stellar Lyman α during the planet’s transit. This gas is understood to be lost from the planet itself, driven by irradiation from the nearby host star. More recently, near-UV transits of one of the most extreme hot Jupiters, WASP-12b, indicated that gas lost from the planet enshrouds the entire planetary system. Several other highly irradiated hot Jupiter hosts show signs of absorbing enshrouding gas from measurements of the flux in their CaII H&K lines. We will present new evidence for absorbing gas around a nearby, bright F-star. This is a mature system, therefore the gas cannot be primordial. It must either have a recent origin or it is being continuously produced. We will discuss a follow-up search for a short-period, evaporating planet around this star.
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Jean Teyssandier
Presentation type: poster
Title:
Torque on an exoplanet from an anisotropic evaporative wind
Abstract:
Winds from short-period Earth and Neptune mass exoplanets, driven by X-ray and EUV radiation from a young star, may evaporate a significant fraction of a planet's mass. If the evaporative wind's momentum flux is not aligned with the planet/star axis, then it can exert a torque on the planet's orbit. We estimate the momentum flux of the evaporative wind from time-dependent one-dimensional hydrodynamical simulations, and derive a lag angle for the direction in which the wind is evaporating. We find that in a narrow regime in planet radius, mass and stellar radiation flux, a wind is capable of exerting a significant torque on the planet's orbit. A close-in Neptune mass planet that loses a large fraction of its mass in a wind could drift a fraction of percent of its semi-major axis. While this is small, it can places constraint on the evolution of resonant pairs such as Kepler 36 b and c.
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Scott Thomas
Presentation type: poster
Title:
Do you want to build a planet?
Abstract:
Planetary interior models are an exciting way of trying to make sense of the diverse range of exoplanets, but how accurate are they and how much information can they give us? We have constructed new models based on the latest equation of state (EOS) information and are examining the effects of temperature dependence in these EOS on icy planets, or "water-worlds". So, if you want to build a planet, come and chat!
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Samantha Thompson
Presentation type: poster
Title:
HARPS3 and the Terra Hunting Experiment
Abstract:
We present an update on the current status of the THE@INT project. THE@INT plans to build and install a close-copy of the HARPS instrument on the Isaac Newton Telescope and undertake a 10-year radial velocity survey to discover Earth-like planets around solar-like stars. A percentage of every night will be used for the Terra Hunting Experiment to obtain long time series data with the best possible sampling and improve the retrieval of low amplitude signals. Survey operations are planned to start in 2018.
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Giovanna Tinetti
Presentation type: institutional summary
Title:
Exoplanet research at University College London
Abstract:
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Oliver Turner
Presentation type: talk
Title:
Targeting Bright Stars with SuperWASP-South
Abstract:
Over the past decade the Wide Angle Search for Planets (WASP) program has been finding planets that push the boundaries of our understanding of planet formation and evolution. In recent years both the North and South installations have changed their observing strategies with the aim of discovering rarer objects to further fill gaps in our knowledge and to test current theory. Here we look at the performance and potential of the new WASP-South instrument, which we modified to target brighter stars.
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Dimitri Veras
Presentation type: talk
Title:
The growing field of post-main-sequence exoplanetary science
Abstract:
All known planet hosts, including the Sun, will become giant stars and then white dwarfs. Therefore, the study of post-main-sequence planetary systems provides a vital window into the past, and includes surface and interior chemical composition data which will be unavailable in the observations of main sequence planets for the foreseeable future. Here I provide a brief review of our current knowledge of post-main-sequence planetary systems, how the UK exoplanet community is already involved in their characterisation and modeling, and the future direction of this research within the UK.
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Hannah Wakeford
Presentation type: talk
Title:
Transmission spectral properties of clouds in the atmospheres of hot Jupiter exoplanets
Abstract:
Clouds play an important role in the atmospheres of planetary bodies. It is expected that, like all the planetary bodies in our solar system, exoplanet atmospheres will also have substantial cloud coverage, and evidence is mounting for clouds in a number of hot Jupiters. To better characterise planetary atmospheres, we need to consider the effects these clouds will have on the observed broadband transmission spectra. We examine the expected cloud condensate species for hot Jupiter exoplanets and the effects of various grain sizes and distributions on the resulting transmission spectra from the optical to infrared, which can be used as a broad framework when interpreting exoplanet spectra. We note that significant infrared absorption features appear in the computed transmission spectrum, the result of vibrational modes between the key species in each condensate, which can potentially be very constraining. While it may be hard to differentiate between individual condensates in the broad transmission spectra, it may be possible to discern different vibrational bonds, which can distinguish between cloud formation scenarios, such as condensate clouds or photochemically generated species. Vibrational mode features are shown to be prominent when the clouds are composed of small sub-micron sized particles and can be associated with an accompanying optical scattering slope. These infrared features have potential implications for future exoplanetary atmosphere studies conducted with JWST, where such vibrational modes distinguishing condensate species can be probed at longer wavelengths.
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Ingo Waldmann
Presentation type: talk
Title:
UCL-ExoLights
Abstract:
The field of exoplanetary spectroscopy is as fast moving as it is new. Permanently at the edge of instrument feasibility, it is as important as it is difficult to find the most optimal and objective methodologies to analysing and interpreting current data. This is particularly true for smaller and fainter Earth and Super-Earth type planets. For low to mid signal to noise observations, we are prone to two sources of biases: 1) Biases in the data reduction and analysis through an inaccurate knowledge of the instrument response function; 2) Biases through prior constraints on the spectral retrieval.
The UCL-ExoLights project works on addressing both these bottle necks. Through the use of machine learning techniques, we have shown that instrument systematics can be objectively de-trended from the science signal with the only prior assumption that both instrument and science are statistically independent from one another. This approach has been validated on both spectroscopic as well as photometric data. Following these approaches we also present a new take on the spectral retrieval of extrasolar planets. Tau-REx (tau-retrieval of exoplanets) is a new line-by-line, atmospheric retrieval framework. In the past the decision on what opacity sources go into an atmospheric model were usually user defined. Manual input can lead to model biases and poor convergence of the atmospheric model to the data. In Tau-REx we have set out to solve this. Through custom built pattern recognition software, Tau-REx is able to rapidly identify the most likely atmospheric opacities from a large number of possible absorbers/emitters (ExoMol or HiTran data bases) and non-parametrically constrain the prior space for the Bayesian retrieval. Together with non-parametric data de-trending of exoplanetary spectra, we can reach an unprecedented level of objectivity in our atmospheric characterisation of these foreign worlds.
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Simon Walker
Presentation type: talk
Title:
A characteristic orbital period of giant planets from the WASP survey
Abstract:
We determine the occurrence rate and orbital period distribution of hot Jupiters using the large sample of confirmed giant planets detected by the WASP survey. The WASP planet sample is the largest collection of confirmed hot Jupiters and is therefore ideal to determine the underlying period distribution.
In order to understand the WASP selection biases we injected synthetic transit signals and determine the recovery fraction using the standard WASP pipeline. We find a sharp peak in occurrence rate at four days, a counterpart to the pile up found in radial velocity surveys. This characteristic period is an observational constraint on models of giant planet migration.
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Christopher Watson
Presentation type: institutional summary
Title:
Exoplanet research at Queen's University Belfast
Abstract:
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Peter Wheatley
Presentation type: institutional summary
Title:
Exoplanet research at Warwick
Abstract:
I will summarise exoplanet research at the University of Warwick.
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David Wilson
Presentation type: talk
Title:
White Dwarfs As Probes Of The Chemistry Of Exo-planetary Systems
Abstract:
Studies of evolved planetary systems at white dwarfs can provide a unique insight into the bulk chemical composition of extrasolar planetary material, which cannot be obtained at main-sequence systems. I will give an overview of the observational and modelling techniques used to study evolved planetary systems, and I will highlight notable results. In particular, I will discuss the overall chemistry of exo-planetary systems in comparison with the Solar System, as well as the potential occurrence of "exotic" planetary compositions.
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Richard Wilson
Presentation type: institutional summary
Title:
Developments at Durham CfAI for characterisation and correction of scintillation noise in high-precision photometry
Abstract:
Atmospheric scintillation is typically the limiting noise source for ground-based photometric observations of bright stars, for both small and large telescopes, and is therefore particularly important in observations of transiting exoplanets. I will summarise recent work at Durham University Centre for Advanced Instrumentation (CfAI) aimed at the characterisation and correction of scintillation noise in high-precision photometry of bright stars, and the implications for TEP observations.
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Mark Wyatt
Presentation type: institutional summary
Title:
Exoplanet research at the IoA Cambridge
Abstract:
I will review exoplanet work undertaken at the Institute of Astronomy, Cambridge. This covers a broad range of topics, including: exoplanet atmospheres and interiors (Madhusudhan), debris disks and planetary system dynamics (Wyatt), protoplanetary disk evolution (Clarke), direct imaging spectroscopy of exoplanets (Parry), transit studies (Hodgkin), and involvement in the GAIA and PLATO missions (Walton).
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John Young
Presentation type: talk
Title:
The Planet Formation Imager
Abstract:
The Planet Formation Imager (PFI) project is an international collaboration to develop the roadmap for the construction of a new near-/mid-infrared interferometric facility designed to image all the major stages of planet formation, from initial dust coagulation, gap formation, evolution of transition disks, mass accretion onto planetary embryos, and eventual disk dispersal. PFI will be able to detect the emission of the newly formed planets themselves over the first 100 Myrs, allowing spectral investigations and also revealing the early dynamical histories of planetary architectures. Science and technical working groups have been formed within the project, and their membership are currently drafting white papers on the science case and technical roadmap respectively. We introduce the Planet Formation Imager (PFI) project (www.planetformationimager.org) and briefly describe possible architectures for the interferometer and the technical advances that will be needed to realise them.
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