Yoshi Nike Emilia Eschen

I'm a PhD student working on the detection and characterisation of planets around compositionally diverse stars and the PLATO mission. I am currently working at ESO in Santiago, Chile with Gaspare Lo Curto and Luca Sbordone.

Research

Detecting and Characterising Planets Around Compositionally Diverse Stars

I am analysing photometric data from space-based missions such as TESS and CHEOPS to determine the radii of planets. For this, I use publicly available TESS data and CHEOPS data through the CHEOPS Guaranteed Observing Time Program in which I lead my own programme, ZGALaxY. I have experience in re-extracting CHEOPS PSF photometry using PIPE and detrending CHEOPS photometry using pycheops as well as detrending ground-based photometry from MuSCAT. On the radial velocity side, I have experience in analysing data from HARPS, HARPS-N, ESPRESSO and CARMENES to determine the planetary masses.

Knowing the planetary density from the observed radius and masses, I perform interior structure modelling for which I using plaNETic, ExoMDN and ExoInt. My research mainly focuses on connecting the interior structure of Super-Earths and Sub-Neptunes to the abundances of the host star. Recently, I led two papers on the two discoveries of an Ultra-Short Period Super-Earth and a Sub-Neptune orbiting the kinematic thick disk star TOI-2345 and the thick disk/Hercules stream star TOI-4311. In addition to characterising the planets with TESS, CHEOPS and HARPS and the stellar properties, I kinematically analysed the stars to place these systems in the context of other well-characterised systems across the galaxy and modelled the interior structure of the planets by combining plaNETic with ExoINT.

To characterise further planetary systems, I lead 4 EPRV programs with HARPS-N, HARPS/NIRPS, HARPS3 (which you can read about here) and CARMENES. To study stellar abundances and identify new exciting host stars for my work, I lead a programme on WEAVE. I have observing experience of more than a total of 100 nights with HARPS and NIRPS on ESO's 3.6m Telescope, HARPS-N and GIANO-B on the Telescopio Nazionale Galileo and WEAVE on the William Herschel Telescope.

As part of my PhD I was an ING student on La Palma. During this time, I conducted observations with WEAVE in LIFU, MOS and mIFU mode for the commissioning and science validation of the instrument. I was organising the ING Journal Club, giving ING and NOT students as well as visiting astronomers the opportunity to present their work in form of a seminar.

Estimating PLATO's Discovery Potential

The PLATO mission will be launched next year with the goal to find a Sun-Earth analogue. However, the optimal observing strategy to enable such a detection is still discussed. To assess PLATO's discovery potential and compare observing strategies, I computed detection sensitivities and compared yields for longer observations of the southern field and the combination of the southern and northern fields.

This project was a continuation of my MSc project, for which I was working with Daniel Bayliss and published a first-author paper focusing on the content of the PLATO field and the detection sensitivities of finding transiting exoplanets with TESS and PLATO. To maintain an updated overview of the planets and planet candidates in PLATO's LOPS2 field, Anna Julia Poser (FU Berlin) and I built a web-tool which can be found here: POPCORN.

Previous Work

I did my undergraduate at the University of Cambridge, followed by a summer internship at the Max Planck Institute for Extraterrestrial Physics. Before starting my MSc, I was a research assistant at MIT working on the LEO-Vetter and applied it to TESS data in which I found 9 new planet candidates around M Dwarfs with Michelle Kunimoto. Additionally, I conducted a search for Exo-Trojans in TESS data with Avi Shporer which I presented at AAS in 2024.

Publications

My first and co-authored publications are listed below. You can also find an overview here.

First Author

• Eschen et al. (submitted): "Assessing PLATO's Discovery Potential across Different Observing Strategies"
• Eschen et al. (2026): "An Ultra-Short Period Super-Earth and a Sub-Neptune Orbiting the K dwarf TOI-4311"
• Eschen & Lafarga (2026): "Orbyts: Searching the PLATO fields for TTVs and Orbital Decay with TESS and CHEOPS"
• Eschen et al. (2025): "An Ultra-Short Period Super-Earth and Sub-Neptune Spanning the Radius Valley Orbiting the Kinematic Thick Disk Star TOI-2345"
• Eschen et al. (2024): "Viewing the PLATO LOPS2 field through the lenses of TESS"
• Eschen & Kunimoto (2024): "9 new M Dwarf Planet Candidates from TESS Including 5 Gas Giants"

Co-Author

• Cabrera et al. (submitted): "Assessment of PLATO Science Performance"
• Egger et al. (2026): "Searching for hot water world candidates with CHEOPS: II. A low-density super-Earth orbiting the K dwarf TOI-2211"
• Heidari et al. (2026): "SOPHIE and TESS characterization of fourteen TESS Objects of Interest: nine planetary systems and five low-mass stellar companions"
• Naponiello et al. (2026): "Refined parameters, formation, and dynamical stability of the wild exoplanet system K2-312=HD 80653"
• Mitchell et al. (2026): "Following up the Kepler field with PLATO: Transit Timing Performance"
• Kliapets et al. (2026): "Variability classification of TESS targets in LOPS2, the first long-pointing field of PLATO. Version 1 of the public variability catalogue"
• Rodel et al. (2026): "TIC-65910228 b / NGTS-38 b, a 180 day transiting warm super-Jupiter"
• Palethorpe et al. (2026): "Constraining Small Planet Compositions for Future Missions"
• Turner, Eschen et al. (2026): "The mass of the exo-Venus Gliese 12 b, as revealed by HARPS-N, ESPRESSO and CARMENES"
• Barragán et al. (2026): "Mass estimates of the young TOI-451 transiting planets: Multidimensional Gaussian Process on stellar spectroscopic and photometric signals"
• Kunimoto et al. (2025): "LEO-Vetter: Fully Automated Flux- and Pixel-Level Vetting of TESS Planet Candidates to Support Occurrence Rates"
• Luque et al. (2025): "Improved characterization of the TOI-2141 system: a dense sub-Neptune with non-transiting inner and outer companions"
• Rauer et al. (2025): " The PLATO mission"
• Rodel et al. (2025): "NGTS-EB-7, an eccentric, long-period, low-mass eclipsing binary"
• Aloisi et al. (2025): "Searching for Exoplanets Born Outside the Milky Way: VOYAGERS Survey Design"

Conferences

• From Stars to Life Workshop, Natal, Brazil, November 2026 - Poster (to attend)
• Planets in the Galactic Context Workshop, New York, US, October 2026 - Poster
• GPRV 2026, Oxford, UK, September 2026 - Poster
• PLATO ESP 2026: Confronting Exoplanets Across Time and Space, Warwick, UK, September 2026 - Talk & Poster
• PLATO Week 18, Oslo, Norway, July 2026 - Talk
• Cool Stars 23, Tokyo, Japan, June 2026 - Talk
• Layers of Understanding, Heidelberg, Germany, April 2026 - Talk
• First Annual Meeting of the DGP, Berlin, Germany, March 2026 - Talk
• Rocky Worlds 4, Groningen, Netherlands, January 2026 - Talk
• Exploring Star-Planet-Disk Connections Conference, Tartu, Estonia, October 2025 - Talk
• PLATO Week 16, Paris, France, October 2025
• CHEOPS Science Team Meeting, Graz, Austria, September 2025
• National Astronomy Meeting, Durham, UK, July 2025 - Talk
• Sixth Workshop on Extremely Precise Radial Velocities, Porto, Portugal, July 2025 - Talk
• PLATO ESP 2025: Planets throughout the Habitable Zone, Marseille, France, June 2025 - Talk & Poster
• Emerging Researchers in Exoplanet Science Symposium, Princeton, US, May 2025 - Talk
• UKEXOM, Leeds, UK, April 2025 - Talk
• CHEOPS Science Team Meeting, Noordwijk, Netherlands, March 2025
• PLATO Week 15, Göttingen, Germany, October 2024
• International Astronautical Congress, Milan, Italy, October 2024 - Talk
• TESS Science Conference 3, Cambridge, US, July 2024 - Talk & Poster
• ESP 2024: PLATO Planetary Systems, Catania, Italy, May 2024 - Talk
• AAS, New Orleans, US, January 2024 - Poster

Observing Programs

Principal Investigator (PI)

• A homogeneous abundance study of planet (candidate) hosting stars, WEAVE
• ZGALaxY, CHEOPS GTO Programme
• Characterising the composition of our nearby Earth-twin Gliese 12 b, HARPS/NIRPS, 9.5 nights
• HARPS3 can push star-planet links into a new regime with TOI-5710, HARPS3, 64.9 hours
• Probing the interiors of Sub-Neptunes orbiting thick disk stars, CARMENES, 4.85 nights
• Testing star-planet compositional connections with the metal-poor star TOI-5115, HARPS-N, 9 hours

Co-Investigator (Co-I)

• PI: Osborn, Mass characterisation of CHEOPS' long-period sub-Neptunes, ESPRESSO + HARPS/NIRPS, 27 hours + 8.2 nights
• PI: Venturini: The nature of small S-type planets: Super-Earths or mini-Neptunes?, ESPRESSO, 136 hours

Seminars

• Probing Star-Planet Chemical Connections: Interior Structures of Small Planets Orbiting Metal-Poor Stars, European Southern Observatory (ESO), Santiago, Chile, 4/2026
• Characterising Small planets around compositionally diverse stars and an Outlook on PLATO's Detection Potential, Geneva Observatory, Geneva, 02/2026
• Compositionally Characterising Small Exoplanets and an Outlook on PLATO, ESTEC, Noordwijk 01/2026
• Filling in the lack of well-characterised small planets orbiting compositional diverse stars and PLATO’s Detection Potential, DLR, Berlin, 01/2026
• Comparing PLATO’s Discovery Potential for different observing strategies, Freie Universität, Berlin, 01/2026
• Interior Structures of Small Planets Orbiting Compositionally-Diverse stars, Freie Universität, Berlin, 01/2026
• PLATO's Discovery Potential, MIT TESS Group, Cambridge, 06/2025

Outreach

• Together with Marina Lafarga Magro I manage the Orbyts Hub in Warwick since Summer 2024. We connect GCSE students with researchers to conduct research projects. For half a year the students and researchers meet weekly to work on their project. The results are presented at the end at a conference. More details about Orbyts can be found here: Orbyts.
• I joined this year's XMaS Scientist Experience as a supervisor, a trip for female Year 12 Physics students to Grenoble. More information about this program can be found here: XMaS Scientist Experience
• In Summer 2025 I taught German high school students about exoplanets in a course called "Is there a planet b?" at the German student academies. In this two-week course the students learned about exoplanets and telescopes, discussed habitability and analysed real data from TESS and CHEOPS themselves.
• I am a volunteer for Warwick's inflatable planetarium and give shows at local schools. For events hosted in Warwick, I regularly give tours of the Marsh Observatory.