33 papers
Spectroscopic follow-up of compact object binary candidates from Gaia DR3: White dwarfs, neutron stars, black holes, and the parallax zeropoint
Kareem El-Badry, David W. Latham, Hans-Walter Rix +12
Astrometry and radial velocities (RVs) from Gaia DR3 yielded orbits for hundreds of thousands of binary systems, including several samples proposed to contain black holes (BHs), ne…
A Galactic intermediate-mass stripped star with a Wolf-Rayet-like wind
Johanna Müller-Horn, Kareem El-Badry, Andreas A. C. Sander +17
Binary interaction in massive stars is expected to produce a large population of intermediate-mass (- M) envelope-stripped stars, yet such objects have remained elusi…
The Twentieth Data Release of the Sloan Digital Sky Survey: First All-Sky BOSS Spectra, eROSITA-SDSS-V Mapper Coordinated Observations, and a Preview of the Local Volume Mapper
SDSS Collaboration, Mojgan Aghakhanloo, David Aguilar +273
The paper describes the twentieth data release (DR20) of the Sloan Digital Sky Survey, providing over 3 million new optical spectra from the SDSS‑V Milky Way, Black Hole, and Local…
Hide and Seek with Gaia. Detectability of Predicted Thin-Disc Metal-Rich RR Lyrae Binaries in Gaia DR3 and DR4
Giuliano Iorio, Pranav Nagarajan, Alexey Bobrick +8
RR Lyrae stars (RRLs) are classical tracers of old stellar populations, yet growing evidence suggests the presence of a metal-rich ([Fe/H]>-0.5), intermediate-age (2-7 Gyr) sub-pop…
BE Lyncis is not a Black Hole Binary: Lessons From Gaia and Hipparcos Astrometry
Pranav Nagarajan, Kareem El-Badry, Thomas J. Maccarone +3
BE Lyncis (BE Lyn) is a well-studied high-amplitude Scuti variable star (HADS). Recently, Niu et al. (2026) analyzed a 39-year baseline of times of maximum light of BE Lyn, re…
Dormant black hole candidates from Gaia DR3 summary diagnostics
Johanna Müller-Horn, Hans-Walter Rix, Kareem El-Badry +4
We present a rigorous identification of candidates for dormant black holes (BHs) and neutron stars (NSs) in binaries using summary statistics from Gaia DR3, rather than full orbita…