Skip to main content Skip to navigation

Mairi O'Brien

About Me

Mairi

I am a fourth-year PhD student in the Astronomy & Astrophysics group at the University of Warwick. My supervisor is Pier-Emmanuel Tremblay and I am funded by the ERC. I study the demographics of the local white dwarf population. I began my PhD in October 2021.

My Research

The 40 pc white dwarf sample is the benchmark volume-limited sample of white dwarfs. This sample was created using Gaia photometry and parallaxes. My first PhD paper involved the confirmation of ~250 new white dwarfs within the 40 pc volume, and the sample is now 99% complete with spectroscopic follow-up.

With atmospheric compositions determined from spectroscopy, we now have accurate parameters such as mass and age for all white dwarfs within 40 pc. My second PhD paperLink opens in a new window focused on the demographics of the unbiased 40 pc sample, including magnetic white dwarfs, binaries, and mass and age distributions.

40pc_map

Accessing Data

Table 3 from O'Brien et al. (2023) is available at CDSLink opens in a new window. Tables 1 and 6 from O'Brien et al. (2024) are available at CDSLink opens in a new window. All tables from O'Brien et al. (2024) are also available to download hereLink opens in a new window.

Publications

First-author:

M. W. O'Brien, P.-E. Tremblay et al. "The 40 pc sample of white dwarfs with GaiaLink opens in a new window". In: MNRAS 527, 3, 8687 (Jan. 2024). arXiv: 2312.02735Link opens in a new window

M. W. O'Brien, P.-E. Tremblay et al. “ Gaia  white dwarfs within 40 pc III: spectroscopic observations of new candidates in the southern hemisphereLink opens in a new windowLink opens in a new windowLink opens in a new window". In: MNRAS 518, 2, 3055 (Jan. 2023). arXiv: 2210.01608 

My ADS publication library is linked hereLink opens in a new window.

Conferences and Seminar Talks

2024:

Talk - EuroWD24 - July 2024 - Barcelona, Spain: Conclusions from the 40 pc sample of Gaia white dwarfs.

Talk [Virtual] - Cool Stars 22 Splinter Session; The Solar Neighbourhood: the Importance of Being Complete - June 2024 - Virtual (San Diego, USA): The 40 pc sample of white dwarfs from Gaia.

Talk - Armagh Observatory Student Discussion - May 2024 - Armagh, UK: Unveiling the demographics of the local white dwarf population with Gaia.

Talk - UCLA Tuesday Lunch Talks - April 2024 - Los Angeles, USA: Unveiling the demographics of the local white dwarf population with Gaia.

Poster - Current Challenges in the Physics of White Dwarf Stars - March 2024 - Santa Fe, New Mexico, USA: The significance of the low-mass issue on the local white dwarf population.

2023:

Poster - Exoplanet Systems and Stellar Life Cycles: Late-Stage and Post-MS Systems - March 2023 - Aspen, USA: Metal-polluted white dwarfs in the local 40 pc volume.

2022:

Talk - EuroWD22 - August 2022 - Tübingen, Germany: Completing the 40 pc sample of Gaia white dwarfs.

Talk - National Astronomy Meeting - July 2022 - Warwick, UK: Completing the 40 pc sample of Gaia white dwarfs.

Telescope Time Awarded

July 2024 - STIS on the Hubble Space Telescope - PI: 5 orbits - GO 17778Link opens in a new window. "Revealing the closest hidden white dwarfs in post-common envelope binaries".

January 2023 - X-Shooter on the ESO Very Large Telescope (VLT) - PI: 4.7 hours - 111.24FZLink opens in a new window. "Ultra-cool White Dwarf Candidates Within 40 pc".

EDI, Outreach & Teaching

2023 - 2024

  • Chair of PG-SSLC (Staff-Student Liaison Committee) - Organise meetings and feed back PG student concerns to staff.

  • Warwick Astronomy Equitea Group: Committee member (Speaker Liaison) - Organise sessions and speakers for our monthly Equitea seminars.

  • Coding with Sophie: Teaching coding to 7 - 11 year olds.

  • Big Bang Science Fair-June 2024.
  • Undergraduate Lab Demonstrator.

2022 - 2023​

  • Physics Welfare & Communication Group: Postgraduate Wellbeing Representative - Organise weekly wellbeing coffee sessions for the physics postgraduate students.

  • Warwick Astronomy Equitea Group: Committee member (Speaker Liaison) - Organise sessions and speakers for our monthly Equitea seminars.

  • Coding with Sophie: Teaching coding to 7 - 11 year olds.

  • Big Bang Science Fair - June 2023.
  • Undergraduate Lab Demonstrator.

  • Undergraduate Exam Invigilator.

2021 - 2022

  • Warwick White Dwarf Group Weekly Meeting Organiser.

  • Warwick Astronomy Knowledge Exchange (WAKE): Ran a workshop and organised group introduction sessions with our white dwarf group.

  • Undergraduate Lab Demonstrator.

  • Undergraduate Exam Invigilator.

Write to:

Mairi O'Brien,

Department of Physics,

University of Warwick,

Coventry CV4 7AL

UK

Office: A1.24, Millburn House

Contact:

Email: Mairi.O-Brien [at] warwick.ac.uk

Twitter: @MairiOBrien