Astronomer and Science Communicator
I am a postdoctoral researcher and science communicator at the Department of Physics and Astronomy at Uppsala University in Sweden, where I work to understand the stars and planets of the southern sky and evangelise the wonders of the Universe to the public. I obtained my PhD in 2021 from the Research School of Astronomy and Astrophysics at the Australian National University (ANU) in Canberra.
I currently am part of the CRIRES+ Consortium and work as part of the Planetary Atmospheres Working Group to understand planets through high-resolution transmission spectroscopy. More broadly, however, my research interests sit somewhere at the intersection of cool stars, exoplanet demographics, stellar benchmarks, and non-traditional analysis techniques.
This largely centres on cool dwarf stars of spectral type M or K, which are the most common kind of star in the Universe, and the most likely to host planets. These stars possess complicated spectra dominated by intense molecular absorption, something which is not well reproduced by current libraries of model spectra—especially at optical wavelengths.
This greatly limits the ability to chemically characterise these stars and their planets, and currently they are arguably best understood via empirical relations, comparison to benchmark systems, or through non-traditional analysis techniques like data-driven methods. My PhD research was focused on providing solutions to some of these challenging topics.
My first project in Rains et al. 2020 used PIONIER, the highest resolution beam combiner on the VLTI, to broaden and verify the existing library of ~1% precision temperature and radius benchmark stars suitable to calibrate current and future surveys in Galactic archaeology.
Rains et al. 2021 involved working to characterise a set of 92 cool TESS candidate exoplanet hosts and their 100 candidate planets and in so doing conduct an investigation into the systematics associated with model cool dwarf spectra, develop a new photometric [Fe/H] relation for isolated cool dwarfs, and broaden the currently small sample of planets around cool stars suitable for studies in exoplanet demographics.
The main extension to my PhD work has been to use the cool dwarf spectra observed as part of Rains et al. 2021 in a data-driven capacity to recover stellar chemistry. When trained on a hand-selected set of benchmarks, my Cannon model is able to recover Teff, log g, [Fe/H], and [Ti/H], as well as gain insight into the giant planet—[Fe/H] correlation for my sample of TESS candidate planet hosts. For preliminary results, see my poster from Cool Stars 21.
Casagrande L., Lin J., Rains A. D., Liu F., Buder S., Horner J., Asplund M., et al., 2021, MNRAS, 507, 2684. doi:10.1093/mnras/stab2304,
Characterization of 92 southern TESS candidate planet hosts and a new photometric [Fe/H] relation for cool dwarfs:
Rains A. D., Žerjal M., Ireland M. J., Nordlander T., Bessell M. S., Casagrande L., Onken C. A., et al., 2021, MNRAS, 504, 5788. doi:10.1093/mnras/stab1167,
A spectroscopically confirmed Gaia-selected sample of 318 new young stars within ∼200 pc:
Žerjal M., Rains A. D., Ireland M. J., Zhou G., Kammerer J., Wallace A., Orenstein B. J., et al., 2021, MNRAS, 503, 938. doi:10.1093/mnras/stab513,
Precision angular diameters for 16 southern stars with VLTI/PIONIER:
Rains A. D., Ireland M. J., White T. R., Casagrande L., Karovicova I., 2020, MNRAS, 493, 2377. doi:10.1093/mnras/staa282, For my complete publication record, check ADS via the button below.
Outside of research, I am both passionate about and heavily involved in science outreach and communication. I believe that science is for everyone and that means it should be accessible to everyone.
Before I left ANU, I was the most senior student member of the Mount Stromlo Observatory outreach team and, since first starting in 2015, delivered more than 170 school visits, stargazing sessions, public talks, and observatory tours.
I've worked with ANU to bring science to regional schools in my home state of Queensland; helped create a series of educational videos produced by the ANU and the Australian Broadcasting Corporation (ABC, Australia's public broadcaster); spoken at science festivals like Pint of Science and National Science Week; given online public talks (What is Your Favourite Planet, and Why is it Jupiter?; and Interferometry: When One Telescope Just Isn't Good Enough) been interviewed on the radio and on podcasts; and have tried my hand at science writing for the Canberra Times (1, 2, 3), and Astronomy Australia.
Additionally, since 2020 I have served on the Australian Capital Territory Coordinating Committee for Australia's National Science Week—a week-long science festival held each August. This sees me working collaboratively to facilitate science communication at large scale to a diverse audience and in 2020—despite the challenges imposed by the COVID-19 pandemic—we successfully reached over 10,000 participants with our large space science-themed showcase event: Satellite Selfie.
This role has allowed me to develop a complementary set of skills to my outreach work, including web design, writing copy, graphic design, organising speakers, emceeing webinars, evaluating seed grant funding applications, and event planning and delivery.
Feel free to reach out if you'd like to work together—I'm always happy to volunteer my time when it comes to science communication!