106 citations · 446 across the 37 of their papers we have counts for
39 papers
OCCAM X. Neutron Capture Abundances with Keck/HIRES & Magellan/MIKE
Natalie R. Myers, Peter M. Frinchaboy, Henrique Reggiani +10
The chemistry of stars provides powerful insight into the history of the Milky Way. With multiple large-sky spectroscopic surveys that are currently available, using chemistry as a…
Radial Velocity Orbital Solutions for Candidate Black Hole and Neutron Star Binary Systems in the Gaia Data Release 3 Catalog
Joshua D. Simon, Casey Y. Lam, Kareem El-Badry +8
We present spectroscopic followup observations of binary systems from the Gaia Data Release 3 (DR3) binary catalog that were selected to have large enough mass functions for their…
Chemical Signatures of AGB Mass Transfer in Gaia White Dwarf Companions
Natsuko Yamaguchi, Kareem El-Badry, Henrique Reggiani +2
We present a homogeneous abundance analysis of 160 main-sequence stars in astrometric white-dwarf + main-sequence (WD+MS) binaries with orbits from Gaia DR3. These systems have AU-…
Giant Planets and Eccentric Orbits Are Common Around Galactic Thick Disc Stars
Thiago Ferreira, Jhon Yana Galarza, Henrique Reggiani +15
Planet formation in the Galactic thick disc is expected to be inefficient---low solid reservoirs, short disc lifetimes, and harsh irradiation environments should conspire to inhibi…
Evidence of 1:1 slope between rocky Super-Earths and their host stars
Mykhaylo Plotnykov, Diana Valencia, Alejandra Ross +2
The relationship between the composition of rocky exoplanets and their host stars is fundamental to understanding planetary formation and evolution. However, previous studies have…
Beyond OCCAM: Measuring Optical Neutron Capture Abundances of Open Cluster Stars
Natalie Myers, Sarah Loebman, Henrique Reggiani +1
Open clusters have long been used to determine ages of stars, as well as calibrate stellar evolution models and other methods of age-dating stellar groups, e.g., gyrochronology, as…
A Spectroscopic Search for Dormant Black Holes in Low-Metallicity Binaries
Pranav Nagarajan, Kareem El-Badry, Henrique Reggiani +9
The discovery of the massive black hole (BH) system Gaia BH3 in pre-release Gaia DR4 data suggests that wide BH binaries with luminous companions may be significantly overrepresent…
Extreme Lithium Depletion in Solar Twins: Challenging Non-Standard Mixing Models
Isabelle Winnick, Jhon Yana Galarza, Henrique Reggiani +12
Lithium (Li) is a powerful tracer of stellar mixing, gradually depleted in solar twins by non-standard transport below the convective zone. Here, we identify six new solar twins wi…
Terrestrial Exoplanet Internal Structure Constraints Enabled by Comprehensive Host Star Characterization Reveal that Terrestrial Planets in Mean-motion Resonances are Water Rich
Alejandra Ross, Henrique Reggiani, Kevin C. Schlaufman +2
Exoplanet mass and radius inferences fundamentally rely on host star mass and radius inferences. Despite the importance of host star mass, radius, and elemental abundance inference…
ASASSN-24fw: Candidate circumplanetary disk occultation of a main-sequence star
Nadia L. Zakamska, Gautham Adamane Pallathadka, Dmitry Bizyaev +24
Dusty disks around planetary and substellar companions in outer reaches of exo-planetary systems can be detected as long-lasting occultations, provided the observer is close to the…
SiO and a super-stellar C/O ratio in the atmosphere of the giant exoplanet WASP-121b
Thomas M. Evans-Soma, David K. Sing, Joanna K. Barstow +15
Refractory elements such as iron, magnesium, and silicon can be detected in the atmospheres of ultrahot giant planets. This provides an opportunity to quantify the amount of refrac…
Cloudy mornings and clear evenings on a gas giant exoplanet
Sagnick Mukherjee, David K. Sing, Guangwei Fu +25
The spectra of exoplanet atmospheres are affected by aerosols (clouds and hazes) of uncertain origin. Proposed aerosol formation mechanisms include gas condensation or photochemica…
The discovery and characterization of Earth-crossing asteroid 2024 YR
Bryce T. Bolin, Josef Hanuš, Larry Denneau +9
We describe observations and physical characteristics of Earth-crossing asteroid 2024 YR, discovered on 2024 December 27 by the Asteroid Terrestrial-impact Last Alert System. T…
Refractory and Volatile Species in the UV-to-IR Transmission Spectrum of Ultra-hot Jupiter WASP-178b with HST and JWST
Joshua D. Lothringer, Katherine A. Bennett, David K. Sing +17
The atmospheres of ultra-hot Jupiters are unique compared to other planets because of the presence of both refractory and volatile gaseous species, enabling a new lens to constrain…
HIP 8522: A Puzzling Young Solar Twin with the Lowest Detected Lithium
Jhon Yana Galarza, Diego Lorenzo-Oliveira, Thiago Ferreira +8
We present HIP 8522, a young solar twin with the lowest detected lithium, potentially a field blue straggler or the result of episodic early accretion. Its stellar parameters ($T_{…
Constraining Extra Mixing during the Main Sequence: What Depletes Lithium Does Not Touch Beryllium
Henrique Reggiani, Jhon Yana Galarza, Diego Lorenzo-Oliveira +4
Measurements of lithium abundances in solar-type stars have shown that standard models of stellar evolution are incapable of explaining the observed depletion as a function of stel…
Detailed abundances of the planet-hosting TOI-1173 A/B system: Possible evidence of planet engulfment in a very wide binary
Jhon Yana Galarza, Henrique Reggiani, Thiago Ferreira +7
Over the last decade, studies of large samples of binary systems identified chemical anomalies, and showed that they might be attributed to planet formation or planet engulfment. H…
Accurate, Precise, and Physically Self-consistent Ages and Metallicities for 400,000 Solar Neighborhood Subgiant Branch Stars
David M. Nataf, Kevin C. Schlaufman, Henrique Reggiani +1
Age is the most difficult fundamental stellar parameter to infer for isolated stars. While isochrone-based ages are in general imprecise for both main sequence dwarfs and red giant…
A Detailed Chemical Study of the Extreme Velocity Stars in the Galaxy
Tyler Nelson, Keith Hawkins, Henrique Reggiani +3
Two decades on, the study of hypervelocity stars is still in its infancy. These stars can provide novel constraints on the total mass of the Galaxy and its Dark Matter distribution…
The Symbiotic X-ray Binary IGR J16194-2810: A Window on the Future Evolution of Wide Neutron Star Binaries From Gaia
Pranav Nagarajan, Kareem El-Badry, Casey Lam +1
We present optical follow-up of IGR J16194-2810, a hard X-ray source discovered by the INTEGRAL mission. The optical counterpart is a red giant at a distance of…
Chemical Diversity on Small Scales -- Abundance Analysis of the Tucana V Ultra-Faint Dwarf Galaxy
Terese T. Hansen, Joshua D. Simon, Ting S. Li +5
The growing number of Milky Way satellites detected in recent years has introduced a new focus for stellar abundance analysis. Abundances of stars in satellites have been used to p…
TOI-1173 A : The First Inflated Super-Neptune in a Wide Binary System
Jhon Yana Galarza, Thiago Ferreira, Diego Lorenzo-Oliveira +8
Among Neptunian mass exoplanets ( M), puffy hot Neptunes are extremely rare, and their unique combination of low mass and extended radii implies very low density ($…
A neutron star candidate in a 2-year orbit
Kareem El-Badry, Joshua D. Simon, Henrique Reggiani +10
We report discovery and characterization of a main-sequence G star orbiting a dark object with mass . The system was discovered via Gaia astrometry and has…
Spectacular nucleosynthesis from early massive stars
Alexander P. Ji, Sanjana Curtis, Nicholas Storm +39
Stars formed with initial mass over 50 Msun are very rare today, but they are thought to be more common in the early universe. The fates of those early, metal-poor, massive stars a…