171 citations · 537 across the 30 of their papers we have counts for
21 papers · 1 filter
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…
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…
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…
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…
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…
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…
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…
The HST large programme on Centauri -- V. Exploring the Ultracool Dwarf Population with Stellar Atmosphere and Evolutionary Modelling
Roman Gerasimov, Adam J. Burgasser, Derek Homeier +5
Brown dwarfs can serve as both clocks and chemical tracers of the evolutionary history of the Milky Way due to their continuous cooling and high sensitivity of spectra to compositi…
New Candidate Extreme T Subdwarfs from the Backyard Worlds: Planet 9 Citizen Science Project
Aaron M. Meisner, Adam C. Schneider, Adam J. Burgasser +29
Schneider et al. (2020) presented the discovery of WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5, which appear to be the first examples of extreme T-type subdwarfs (esdTs…
The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs
J. Davy Kirkpatrick, Christopher R. Gelino, Jacqueline K. Faherty +49
We present final Spitzer trigonometric parallaxes for 361 L, T, and Y dwarfs. We combine these with prior studies to build a list of 525 known L, T, and Y dwarfs within 20 pc of th…
Spitzer Follow-up of Extremely Cold Brown Dwarfs Discovered by the Backyard Worlds: Planet 9 Citizen Science Project
Aaron M. Meisner, Jacqueline K. Faherty, J. Davy Kirkpatrick +40
We present Spitzer follow-up imaging of 95 candidate extremely cold brown dwarfs discovered by the Backyard Worlds: Planet 9 citizen science project, which uses visually perceived…
WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5: The First Extreme T-type Subdwarfs?
Adam C. Schneider, Adam J. Burgasser, Roman Gerasimov +23
We present the discoveries of WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5, two low-temperature (12001400 K), high proper motion T-type subdwarfs. Both objects were d…