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Cyclotron emitting magnetic white dwarfs in post common envelope binaries discovered with the Zwicky Transient Facility
J. van Roestel, A. C. Rodriguez, P. Szkody +20
We present the discovery of 14 new (and recovery of 4 known) low accretion rate magnetic white dwarfs in post-common envelope binaries that emit strong cyclotron emission using the…
Mixed origins: strong natal kicks for some black holes and none for others
Pranav Nagarajan, Kareem El-Badry
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…
Eccentricities of Close Stellar Binaries
Yanqin Wu, Sam Hadden, Janosz Dewberry +2
Orbits of stellar binaries are in general eccentric. These eccentricities encode information about their early lives. Here, we use thousands of main-sequence binaries from the Gaia…
The Nature of Optical Afterglows Without Gamma-ray Bursts: Identification of AT2023lcr and Multiwavelength Modeling
Maggie L. Li, Anna Y. Q. Ho, Geoffrey Ryan +29
In the past few years, the improved sensitivity and cadence of wide-field optical surveys have enabled the discovery of several afterglows without associated detected gamma-ray bur…
A Fast, Analytic Empirical Model of the Gaia Data Release 3 Astrometric Orbit Catalog Selection Function
Casey Y. Lam, Kareem El-Badry, Joshua D. Simon
In June 2022, the Gaia mission released a catalog of astrometric orbital solutions for 168,065 binary systems, by far the largest such catalog to date. The catalog's selection func…
A generative model for Gaia astrometric orbit catalogs: selection functions for binary stars, giant planets, and compact object companions
Kareem El-Badry, Casey Lam, Berry Holl +4
Astrometry from Gaia DR3 has produced a sample of 170,000 Keplerian orbital solutions, with many more anticipated in the next few years. These data have enormous potential to…
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_{…
A Low Metallicity Massive Contact Binary Star System Candidate in WLM identified by Hubble and James Webb Space Telescope imaging
Maude Gull, Daniel R. Weisz, Kareem El-Badry +15
We present archival HST and JWST ultraviolet through near infrared time series photometric observations of a massive minimal-contact binary candidate in the metal-poor galaxy WLM (…
A search for self-lensing binaries with TESS and constraints on their occurrence rate
Natsuko Yamaguchi, Kareem El-Badry, Nicholas M. Sorabella
Five self-lensing binaries (SLBs) have been discovered with Kepler light curves. They contain white dwarfs (WDs) in AU-scale orbits that gravitationally lens solar-type companions.…
Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. I. Methods, Short-Timescale Variables, Binary Candidates, and the Unusual Nucleus of WeSb 1
Soumyadeep Bhattacharjee, S. R. Kulkarni, Albert K. H. Kong +16
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 int…
An Earth-Mass Planet and a Brown Dwarf in Orbit Around a White Dwarf
Keming Zhang, Weicheng Zang, Kareem El-Badry +8
Terrestrial planets born beyond 1-3 AU have been theorized to avoid being engulfed during the red-giant phases of their host stars. Nevertheless, only a few gas-giant planets have…
Cataclysmic Variables and AM CVn Binaries in SRG/eROSITA + Gaia: Volume Limited Samples, X-ray Luminosity Functions, and Space Densities
Antonio C. Rodriguez, Kareem El-Badry, Valery Suleimanov +22
We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 and \textit{Gaia} DR3 using an X-ray + optical color-c…
Ultraviolet spectroscopy of the supernova Ia hypervelocity runaway white dwarf J0927-6335
Klaus Werner, Kareem El-Badry, Boris T. Gänsicke +1
The hot white dwarf (WD) J0927-6335 (Gaia DR3 5250394728194220800, effective temperature T = 60,000 K, surface gravity log g = 7) was detected as the fastest known Gala…
The companion mass distribution of post common envelope hot subdwarf binaries: evidence for boosted and disrupted magnetic braking?
Lisa Blomberg, Kareem El-Badry, Katelyn Breivik +6
We measure the mass distribution of main-sequence (MS) companions to hot subdwarf B stars (sdBs) in post-common envelope binaries (PCEBs). We carried out a spectroscopic survey of…
Searching for New Cataclysmic Variables in the Chandra Source Catalog
Ilkham Galiullin, Antonio C. Rodriguez, Kareem El-Badry +14
Cataclysmic variables (CVs) are compact binary systems in which a white dwarf accretes matter from a Roche-lobe-filling companion star. In this study, we searched for new CVs in th…
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…
Validation of Gaia DR3 orbital and acceleration solutions with hierarchical triples
Pranav Nagarajan, Kareem El-Badry
Using data from Gaia DR3, we construct a sample of 14,791 gravitationally bound wide pairs in which one of the components is an unresolved binary with an astrometric orbital or acc…
Once a Triple, Not Always a Triple: The Evolution of Hierarchical Triples that Yield Merged Inner Binaries
Cheyanne Shariat, Smadar Naoz, Kareem El-Badry +4
More than half of all main-sequence (MS) stars have one or more companions, and many of those with initial masses <8 M are born in hierarchical triples. These systems featu…
Supernova Shocks Cannot Explain the Inflated State of Hypervelocity Runaways from White Dwarf Binaries
Aakash Bhat, Evan B. Bauer, Rüdiger Pakmor +5
Recent observations have found a growing number of hypervelocity stars with speeds of km\,s which could have only been produced through thermonuclear su…
Autonomous Disentangling for Spectroscopic Surveys
Rhys Seeburger, Hans-Walter Rix, Kareem El-Badry +2
A suite of spectroscopic surveys is producing vast sets of stellar spectra with the goal of advancing stellar physics and Galactic evolution by determining their basic physical pro…
On the formation of a black hole in a low-metallicity binary
Kareem El-Badry
A black hole (BH) was recently discovered in an 11.6-year binary only 590 pc from the Sun. The system, Gaia BH3, contains a low-metallicity giant ($\rm…
Wide post-common envelope binaries from Gaia: orbit validation and formation models
Natsuko Yamaguchi, Kareem El-Badry, Natalie Rees +3
Astrometry from {\it 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 orb…
No longer impossible: the self-lensing binary KIC 8145411 is a triple
Natsuko Yamaguchi, Kareem El-Badry, David R. Ciardi +5
Five self-lensing binaries (SLBs) have been discovered with data from the \textit{Kepler} mission. One of these systems is KIC 8145411, which was reported to host an extremely low…
A population of neutron star candidates in wide orbits from Gaia astrometry
Kareem El-Badry, Hans-Walter Rix, David W. Latham +10
We report discovery and spectroscopic follow-up of 21 astrometric binaries containing solar-type stars and dark companions with masses near 1.4 . The simplest interpreta…