UC San Diego Cool Star Lab
Welcome to the homepage of the UC San Diego Cool Star Lab! Feel free to use the links below to learn about our research, teaching, and community activities, and meet our present and past members.
In the News
UCSD has announced the formation of a new Department of Astronomy and Astrophysics! Two A&A major programs and a minor will start in Fall 2024 (read more... and visit the Department webpage)
Graduating PhD student Christian Aganze is one of ten Stanford Science Fellows starting a 5-year postdoctoral position this Fall. Congratulations Christian! (read more...)
Cool Star Lab postdoctoral scholar Christopher Theissen was recently featured in a UC San Diego Today article highlighting the campus's fantastic postdocs! (read more...)
UCSD's new Astronomy Graduate Program is wrapping up its first academic year! Learn about the motivation for the program and the experiences of the inaugural class in an article featured in UC San Diego Today (read more...)
The study of Population III star detectability led by former CSL undergraduate Mikaela Larkin was recently singled out as a Research Highlight by Nature Astronomy (read the highlight and the article).
Christian Aganze was selected as an honorable mention for the Bouchet Graduate Honor Society, co-founded in 2005 by Yale and Howard Universities and named for Edward Alexander Bouchet, the first African American doctoral recipient in the United States. Congratulations Christian!
Cool Star Lab researchers contributed to the discovery of the first Y dwarf binary, WISE J0336-0143AB, identified with JWST/NIRCam. The close pair is separated by less than 1 AU, and the secondary has a mass near or below the deuterium fusion limit, often consider the boundary between brown dwarf and planetary masses. The article has been accepted for publication in ApJ Letters (read the paper at ApJ Letters).
Cool Star Lab researchers helped characterize the low-mass stellar host of the double-planet system TOI-2096. TESS and ground-based monitoring show that this system contains both a super-Earth and a mini-Neptune orbiting a star less than a quarter the mass of the Sun. The CSL team obtained optical spectroscopy with Kast on the Lick Shane Telescope that determined the host star's spectral type, temperature, and metallicity. (read the paper at Astronomy & Astrophysics).
Cool Star Lab undergraduates Tianxing Zhou, Delilah Jacobsen, and Brigette Vazquez-Segovia have reported a new sample of benchmark ultracool dwarfs, based on co-moving systems identified by Gaia. These include 100 systems within 100 pc of the Sun that currently lack spectroscopic characterization (read the paper at AAS Research Notes)
Recent CSL PhD recipient Dino Hsu reported the discovery of the shortest-period ultracool dwarf binary system, LP 413-53AB, based on multiple epochs of Keck/NIRSPEC measurements. This remarkable binary has an orbit of only 17 hours, and its components appear to straddle the hydrogen fusion mass limit (read the paper in ApJ Letters).
The Cool Star Lab Machine Learning group recently published a Research Note demonstrating spectral binary identification with a random forest classifier. The paper was led by undergraduate researcher Malina Desai. (read the paper at RNAAS)
The Cool Star Lab contributed to the discovery of an extremely red L/T dwarf by the Backyard Worlds program, which is likely a planetary mass object in the 22 Myr-old Beta Pic moving group. The CSL team obtained the spectrum of this unique young source with the NIRES spectrograph at Keck Observatory (read the paper in ApJ Letters).
Adam Burgasser contributed to the discovery of the first brown dwarf to be found with JWST, a late T dwarf 570-720 pc from the Sun (read the paper at ApJ Letters)
Undergraduate researcher Mikaela Larkin, mentored by graduate student Roman Gerasimov, led a study on the spectral properties and detectability of magnified Population III stars with JWST (read the paper at AJ)
Summer research student and Lamat Institute scholar Julissa Villalobos Valencia led a spectroscopic study of the M dwarf companion to the bright star µ Virgenes (read the paper at AAS Research Notes)
In the Community
Adam Burgasser was a recipient of the 2023 UCSD School of Physical Science EDI Excellence Award, for his work on developing antiracism seminars and courses in Physics and Astronomy. (read more...)
Cool Star Lab members Delilah Jacobsen and Natalie Lam were among several student leaders from the Advocating for and Representing Minority Students (ARMS) group to co-host with the UCSD Black Studies Project the first ARMS-BSP symposium, featuring astronomer and artist Prof. Nia Imara (read more...)
CSL undergraduate researchers earned top honors as recipients of the UCSD School of Physical Sciences Dean's Undergraduate Excellence Awards: Malina Desai, Juan Diego Draxl Giannoni, Natalie Lam, and Deliliah Jacobsen were among 34 recipients selected from other 4,000 physical science majors. Congratulations to our outstanding undergraduates!
Adam Burgasser and Cool Star Lab members will be hosting an international group of artists to discuss art-science collaborations, as part of the INSITE Lab program. (learn more about INSITE)
Adam Burgasser, in his role as one of three Vice-Presidents for the American Astronomical Society, helped organize a AAS national meeting in Seattle this January that drew over 3,000 astronomers from around the world (learn more...)
Adam Burgasser represented UCSD and the American Astronomical Society at the 2022 SACNAS meeting in Puerto Rico (learn more...)
Cool Star Lab welcomes two new graduate students to our group in Fall 2022: Preethi Karpoor & Emma Softich. Preethi and Emma are part of the inaugural class of the new Astronomy PhD program at UCSD (learn more...)
Cool Star Lab team members participated in the 2022 Southeast Science and Art Expo at the Malcolm X Library (learn more...)