171 citations · 537 across the 30 of their papers we have counts for
32 papers
JWST Observations of the Metal-poor T Dwarf WISEA J155349.96+693355.2: The First Brown Dwarf Associated with the Gaia-Enceladus Milky Way Substructure
Aaron M. Meisner, Adam J. Burgasser, Chih-Chun Hsu +15
We present JWST NIRSpec and MIRI observations of the metal-poor T dwarf WISEA J155349.96+693355.2. The combined NIRSpec/prism plus MIRI/LRS spectrum (R ~ 100) provides 0.6-12 m…
Metal-poor Brown Dwarf Kinematics from JWST NIRSpec Spectroscopy
Chih-Chun Hsu, Christopher A. Theissen, Adam J. Burgasser +14
Galactic archaeology relies on stellar kinematics and chemical abundances to identify various stellar populations and associations. With JWST, Galactic archaeology of ancient metal…
A High-Resolution Spectroscopic Survey of Directly Imaged Companion Hosts: III. Characterization of the Cold Imaged Planet Hosts AF Lep A and Indi A
Aneesh Baburaj, Quinn M. Konopacky, Christopher A. Theissen +3
JWST has enabled the measurement of carbon, oxygen, and sulfur abundances in the atmospheres of directly imaged planets. Interpretation of these abundances from a planet formation…
Evidence of Supernova Between Formation of Stellar Populations in a Globular Cluster
Evan N. Kirby, Roman Gerasimov, Alice Cai +3
Globular clusters do not undergo conventional chemical evolution driven by supernova enrichment. Instead, they exhibit unique abundance patterns of the light elements, which cannot…
Galactic Archaeology with the Subaru `Ōnohi`ula Prime Focus Spectrograph Strategic Program
Masashi Chiba, Rosemary F. G. Wyse, Evan N. Kirby +48
The recently commissioned Subaru `Ōnohi`ula Prime Focus Spectrograph (PFS) will obtain spectra from nearly 2,400 fibers that cover 1.24 square degrees. The 360 night Subaru Strateg…
TOI-4616 b: a benchmark Earth-sized planet transiting a nearby M4 dwarf
F. Zong Lang, B. O. Demory, Y. Gomez Maqueo Chew +44
Rocky exoplanets are particularly abundant around M-type stars. Their small radii and low luminosities provide favourable conditions for detecting transiting terrestrial planets an…
A High-Resolution Spectroscopic Survey of Directly Imaged Companion Hosts: II. Diversity in C/O Ratios among Host Stars
Aneesh Baburaj, Quinn M. Konopacky, Christopher A. Theissen +2
The era of JWST has enabled measurements of abundances of elements such as C, O, and even Na, S, K, and Fe in planetary atmospheres to very high precisions (0.1 dex). Accurat…
Observation of undepleted phosphine in the atmosphere of a low-temperature brown dwarf
Adam J. Burgasser, Eileen C. Gonzales, Samuel A. Beiler +16
The atmospheres of low-temperature brown dwarfs and gas giant planets are expected to contain the phosphine molecule, PH However, previous observations have shown much lower ab…
Population-Dependent r-process Scatter in the Globular Cluster M15
Lauren E. Henderson, Roman Gerasimov, Evan N. Kirby
Multiple populations, defined by correlations between light element abundances, are an almost ubiquitous property of globular clusters. On the other hand, dispersions among the hea…
Neutron-capture Element Abundances of 491 Stars in Milky Way Dwarf Satellite Galaxies from Medium-Resolution Spectra
Lauren E. Henderson, Evan N. Kirby, Mithi A. C. de los Reyes +2
The chemical compositions of evolved stars in Local Group dwarf spheroidal galaxies (dSphs) provide insight into the galaxy's past star formation and nucleosynthesis. Neutron-captu…
New Cold Subdwarf Discoveries from Backyard Worlds and a Metallicity Classification System for T Subdwarfs
Adam J. Burgasser, Adam C. Schneider, Aaron M. Meisner +36
We report the results of a spectroscopic survey of candidate T subdwarfs identified by the Backyard Worlds: Planet 9 program. Near-infrared spectra of 31 sources with red co…
A High-Resolution Spectroscopic Survey of Directly Imaged Companion Hosts: I. Determination of diagnostic stellar abundances for planet formation and composition
Aneesh Baburaj, Quinn M. Konopacky, Christopher A. Theissen +6
We present the first results of an extensive spectroscopic survey of directly imaged planet host stars. The goal of the survey is the measurement of stellar properties and abundanc…
Discovery of a Hypervelocity L Subdwarf at the Star/Brown Dwarf Mass Limit
Adam J. Burgasser, Roman Gerasimov, Kyle Kremer +18
We report the discovery of a high velocity, very low-mass star or brown dwarf whose kinematics suggest it is unbound to the Milky Way. CWISE J124909.08+362116.0 was identified by c…
Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star SPECULOOS-3
Michaël Gillon, Peter P. Pedersen, Benjamin V. Rackham +81
Located at the bottom of the main sequence, ultracool dwarf stars are widespread in the solar neighbourhood. Nevertheless, their extremely low luminosity has left their planetary p…
JWST Imaging of the Closest Globular Clusters -- II. Discovery of Brown Dwarfs in NGC 6397 and Measurement of Age from the Brown Dwarf Cooling Sequence, using SANDee - a New Grid of Model Isochrones across the Hydrogen-Burning Limit
Roman Gerasimov, Luigi R. Bedin, Adam J. Burgasser +4
Globular clusters contain vast repositories of metal-poor stars that represent some of the oldest stellar generations in the Universe. The archaeological footprint of early Galacti…
89 New Ultracool Dwarf Co-Moving Companions Identified With The Backyard Worlds: Planet 9 Citizen Science Project
Austin Rothermich, Jacqueline K. Faherty, Daniella Bardalez-Gagliuffi +43
We report the identification of 89 new systems containing ultracool dwarf companions to main sequence stars and white dwarfs, using the citizen science project Backyard Worlds: Pla…
The Brown Dwarf Kinematics Project (BDKP). VI. Ultracool Dwarf Radial and Rotational Velocities from SDSS/APOGEE High-resolution Spectroscopy
Chih-Chun Hsu, Adam J. Burgasser, Christopher A. Theissen +11
We present precise measurements of radial (RV) and projected rotational () velocities, effective temperatures, and surface gravities of a sample of 258 M6 to L2 dwarfs wi…
The Initial Mass Function Based on the Full-sky 20-pc Census of 3,600 Stars and Brown Dwarfs
J. Davy Kirkpatrick, Federico Marocco, Christopher R. Gelino +85
A complete accounting of nearby objects -- from the highest-mass white dwarf progenitors down to low-mass brown dwarfs -- is now possible, thanks to an almost complete set of trigo…
Exploring the Chemistry and Mass Function of the Globular Cluster 47 Tucanae with New Theoretical Color-Magnitude Diagrams
Roman Gerasimov, Adam J. Burgasser, Ilaria Caiazzo +4
Despite their shared origin, members of globular clusters display star-to-star variations in composition. The observed pattern of element abundances is unique to these stellar envi…
CWISE J105512.11+544328.3: A Nearby Y Dwarf Spectroscopically Confirmed with Keck/NIRES
Grady Robbins, Aaron M. Meisner, Adam C. Schneider +17
Y dwarfs, the coolest known spectral class of brown dwarfs, overlap in mass and temperature with giant exoplanets, providing unique laboratories for studying low-temperature atmosp…
UNCOVER: JWST Spectroscopy of Three Cold Brown Dwarfs at Kiloparsec-scale Distances
Adam J. Burgasser, Rachel Bezanson, Ivo Labbe +19
We report JWST/NIRSpec spectra of three distant T-type brown dwarfs identified in the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) survey of…
Extragalactic Star Cluster Science with the Nancy Grace Roman Space Telescope's High Latitude Wide Area Survey and the Vera C. Rubin Observatory
Kristen C. Dage, Christopher Usher, Jennifer Sobeck +22
The Nancy Grace Roman Telescope's High Latitude Wide Area Survey will have a number of synergies with the Vera Rubin Observatory's Legacy Survey of Space and Time (LSST), particula…
Characterization of Population III Stars with Stellar Atmosphere and Evolutionary Modeling and Predictions of their Observability with the James Webb Space Telescope
Mikaela M. Larkin, Roman Gerasimov, Adam J. Burgasser
Population III stars were the first stars to form after the Big Bang, and are believed to have made the earliest contribution to the metal content of the universe beyond the produc…
A Wide Planetary Mass Companion Discovered Through the Citizen Science Project Backyard Worlds: Planet 9
Jacqueline K. Faherty, Jonathan Gagne, Mark Popinchalk +24
Through the Backyard Worlds: Planet 9 citizen science project we discovered a late-type L dwarf co-moving with the young K0 star BD+60 1417 at a projected separation of 37" or 1662…