144 citations · 704 across the 25 of their papers we have counts for
21 papers · 1 filter
BLG723.31.34651 as an eclipsing Roche lobe-filling sdOB+WD binary
Alekzander Kosakowski, Charles E. Derbyshire, Sydney Jetton +1
We present a detailed observational analysis of BLG723.31.34651, the fourth reported eclipsing member of the class of Roche lobe-filling hot subdwarfs, using time series spectrosco…
Spectroscopic follow-up of hot subdwarf variables found in ZTF -- Atmospheric and fundamental properties of radial-mode sdB pulsators
Corey W. Bradshaw, Thomas Kupfer, Alekzander R. Kosakowski +2
Hot subdwarf variables (sdBVs) that display large-amplitude (1%), short-period variability, as a result of radial-mode pulsations, have recently become objects of interest as th…
A New LISA-Detectable Type Ia Supernova Progenitor in the Southern Sky: SMSS J1138-5139
Alekzander Kosakowski, Matti Dorsch, Warren R. Brown +3
We present the discovery and analysis of a nearby eclipsing ultra-compact accreting binary at coordinates 11:38:10.91 51:39:49.15 (SMSS J11385139), the first well-constrained…
Massive White Dwarfs in the 100 pc Sample: Magnetism, Rotation, Pulsations, and the Merger Fraction
Gracyn Jewett, Mukremin Kilic, Pierre Bergeron +6
We present a detailed model atmosphere analysis of massive white dwarfs with and K in the Montreal White Dwarf Database 100 pc sample and…
Discovery of a Magnetic Double-Faced DBA White Dwarf
Adam Moss, P. Bergeron, Mukremin Kilic +4
We report the discovery of spectroscopic variations in the magnetic DBA white dwarf SDSS J091016.43+210554.2. Follow-up time-resolved spectroscopy at the Apache Point Observatory (…
Electromagnetic characterization of the LISA verification binary ZTF J05265934
Alekzander Kosakowski, Thomas Kupfer, P. Bergeron +1
We present an analysis of new and archival data to the 20.506-minute LISA verification binary J052610.42593445.32 (J05265934). Our joint spectroscopic and photometric analysi…
The ELM Survey South. II. Two dozen new low mass white dwarf binaries
Alekzander Kosakowski, Warren R. Brown, Mukremin Kilic +5
We present the results from our ongoing spectroscopic survey targeting low mass white dwarf binaries, focusing on the southern sky. We used a Gaia DR2 and eDR3 based selection and…
The Merger Fraction of Ultramassive White Dwarfs
Mukremin Kilic, Adam G. Moss, Alekzander Kosakowski +6
We search for merger products among the 25 most massive white dwarfs in the Montreal White Dwarf Database 100 pc sample through follow-up spectroscopy and high-cadence photometry.…
The ELM Survey. IX. A Complete Sample of Low Mass White Dwarf Binaries in the SDSS Footprint
Warren R. Brown, Mukremin Kilic, Alekzander Kosakowski +1
We present the discovery of 17 double white dwarf (WD) binaries from our on-going search for extremely low mass (ELM) <0.3 Msun WDs, objects that form from binary evolution. Gaia p…
Four new deeply-eclipsing white dwarfs in ZTF
Alekzander Kosakowski, M. Kilic, W. R. Brown +2
We present the results of a search for deeply-eclipsing white dwarfs in the ZTF Data Release 4. We identify nine deeply-eclipsing white dwarf candidates, four of which we followed…
An Isolated White Dwarf with a 70 second Spin Period
Mukremin Kilic, Alekzander Kosakowski, Adam G. Moss +2
We report the discovery of an isolated white dwarf with a spin period of 70 s. We obtained high speed photometry of three ultramassive white dwarfs within 100 pc, and discovered si…
The Discovery of Two LISA Sources within 0.5 kpc
Mukremin Kilic, Warren R. Brown, A. Bedard +1
We report the discovery of the brightest detached binary white dwarfs with periods less than an hour, which provide two new gravitational wave verification binaries for the Laser I…
Multi-band light curve analysis of the 40.5-minute period eclipsing double-degenerate binary SDSS J082239.54304857.19
Alekzander Kosakowski, Mukremin Kilic, Warren R. Brown
We present the Apache Point Observatory BG40 broadband and simultaneous Gemini -band and -band high-speed follow-up photometry observations and analysis of the 40.5 minute pe…
The 100 pc White Dwarf Sample in the SDSS Footprint
Mukremin Kilic, P. Bergeron, Alekzander Kosakowski +3
We present follow-up spectroscopy of 711 white dwarfs within 100 pc, and present a detailed model atmosphere analysis of the 100 pc white dwarf sample in the SDSS footprint. Our sp…
The ELM Survey South. I. An Effective Search for Extremely Low Mass White Dwarfs
Alekzander Kosakowski, Mukremin Kilic, Warren R. Brown +1
We begin the search for extremely-low mass (, ELM) white dwarfs (WDs) in the southern sky based on photometry from the VST ATLAS and SkyMapper surveys. We use a…
A 1201 s Orbital Period Detached Binary: the First Double Helium Core White Dwarf LISA Verification Binary
Warren R. Brown, Mukremin Kilic, A. Bedard +2
We report the discovery of a 1201 s orbital period binary, the third shortest-period detached binary known. SDSS J232230.20+050942.06 contains two He-core white dwarfs orbiting wit…
Two new Double-lined Spectroscopic Binary White Dwarfs
Mukremin Kilic, A. Bedard, P. Bergeron +1
We present radial velocity observations of four binary white dwarf candidates identified through their over-luminosity. We identify two new double-lined spectroscopic binary system…
The ELM Survey. VIII. 98 Double White Dwarf Binaries
Warren R. Brown, Mukremin Kilic, Alekzander Kosakowski +7
We present the final sample of 98 detached double white dwarf (WD) binaries found in the Extremely Low Mass (ELM) Survey, a spectroscopic survey targeting <0.3 Msun He-core WDs com…
A Refined Search for Pulsations in White Dwarf Companions to Millisecond Pulsars
Mukremin Kilic, J. J. Hermes, A. H. Corsico +7
We present optical high-speed photometry of three millisecond pulsars with low-mass () white dwarf companions, bringing the total number of such systems with follo…
Periodic optical variability and debris accretion in white dwarfs: a test for a causal connection
Na'ama Hallakoun, Dan Maoz, Eric Agol +9
Recent Kepler photometry has revealed that about half of white dwarfs (WDs) have periodic, low-level (~ 1e-4 - 1e-3), optical variations. Hubble Space Telescope (HST) ultraviolet s…
Discovery of a Detached, Eclipsing 40 min Period Double White Dwarf Binary and a Friend: Implications for He+CO White Dwarf Mergers
Warren R. Brown, Mukremin Kilic, Alekzander Kosakowski +1
We report the discovery of two detached double white dwarf (WD) binaries, SDSS J082239.546+304857.19 and SDSS J104336.275+055149.90, with orbital periods of 40 and 46 min, respecti…