Search Publications
Cataclysmic Variables and AM CVn Binaries in SRG/eROSITA + Gaia: Volume Limited Samples, X-Ray Luminosity Functions, and Space Densities
Mori, Kaya; Ramsay, Gavin; Riddle, Reed +22 more
We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 and Gaia DR3 using an X-ray + optical color–color diagram (the "X-ray Main Sequence"). This tool identifies all CV subtypes, including magnetic and low-accretion rate systems, in contrast to most previous surveys. We find 2…
Mixed Origins: Strong Natal Kicks for Some Black Holes and None for Others
El-Badry, Kareem; Nagarajan, Pranav
Using stellar kinematic data from Gaia DR3, we revisit constraints on black hole (BH) natal kicks from observed accreting and detached BH binaries. We compare the space velocities and Galactic orbits of a sample of 12 BHs in the Galactic disk with well-constrained distances to their local stellar populations, for which we obtain proper motions and…
Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. I. Methods, Short-timescale Variables, and the Unusual Nucleus of WeSb 1
Kulkarni, S. R.; Riddle, Reed; Kong, Albert K. H. +16 more
A complete understanding of the central stars of planetary nebulae (CSPNe) remains elusive. Over the past several decades, time-series photometry of CSPNe has yielded significant results including, but not limited to, discoveries of nearly 100 binary systems, insights into pulsations and winds in young white dwarfs, and studies of stars undergoing…
The T16 Project: Image Subtraction Light Curves from TESS Cycle 1 Full-frame Images for Stars with T < 16
Hartman, Joel D.; Bakos, Gáspár Á.; Bouma, Luke G. +1 more
We present 83,717,159 light curves for 56,401,549 stars with T < 16 mag observed in the Full-Frame Images (FFIs) of Cycle 1 of the NASA TESS mission. These light curves were extracted from subtracted images produced by the Cluster Difference Imaging Survey. We make public the raw image subtraction light curves, together with light curves de-tre…
A Link Between White Dwarf Pulsars and Polars: Multiwavelength Observations of the 9.36-minute Period Variable Gaia22ayj
Mori, Kaya; Riddle, Reed; Szkody, Paula +30 more
White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host a strong (B ≳ 1 MG) magnetic field. However, the origin and evolution of WD magnetism remain under debate. Two WD pulsars, AR Sco and J191213.72–441045.1 (J1912), have been found, which are non-accreting b…
Polarization and Interstellar Extinction Towards the Open Star Cluster NGC 6633
Topasna, G. A.; Kaltcheva, N. T.; Kirk, N. E.
We present optical polarization data of 110 stars in the direction of NGC 6633. From multi-wavelength BVRI measurements of 64 of these stars we obtained a wavelength of maximum polarization that yielded an estimate of total-to-selective extinction ratio RV = 3.18 ± 0.04 over the observed region. The distribution of the polarization posi…
Wide Post-common Envelope Binaries from Gaia: Orbit Validation and Formation Models
El-Badry, Kareem; Mazeh, Tsevi; Yamaguchi, Natsuko +3 more
Astrometry from Gaia DR3 has enabled the discovery of a sample of 3000+ binaries containing white dwarfs (WD) and main-sequence (MS) stars in relatively wide orbits, with orbital periods P orb = (100–1000) days. This population was not predicted by binary population synthesis models before Gaia and—if the Gaia orbits are robust—likely r…
High-precision Astrometry and Photometry with the JWST/MIRI Imager
Law, David R.; Hines, Dean C.; Álvarez-Márquez, Javier +8 more
Astrometry is one of the main pillars of astronomy, and one of its oldest branches. Over the years, an increasing number of astrometric works by means of Hubble Space Telescope (HST) data have revolutionized our understanding of various phenomena. With the launch of JWST, it becomes almost instinctive to want to replicate or improve these results …
Global Parameters of Eight W UMa-type Binary Systems
Poro, Atila; Paki, Ehsan; Michel, Raul +1 more
Multiband photometric investigations for eight binary systems of the W Ursae Majoris-type are presented. Six systems are presented for the first time to analyze their light curves. All the analyzed systems have a temperature below 5000 K and an orbital period of less than 0.28 days. We extracted primary and secondary minima from the ground-based o…
ESPRESSO Observations of Gaia BH1: High-precision Orbital Constraints and no Evidence for an Inner Binary
Triaud, Amaury H. M. J.; Bieryla, Allyson; Rix, Hans-Walter +9 more
We present high-precision radial velocity observations of Gaia BH1, the nearest known black hole (BH). The system contains a solar-type G star orbiting a massive dark companion, which could be either a single BH or an inner BH + BH binary. A BH + BH binary is expected in some models where Gaia BH1 formed as a hierarchical triple, which is attracti…