Related papers: Insights into internal effects of common-envelope …

We present follow-up studies of three ultracompact hot subdwarf binaries. Using data from the Zwicky Transient Facility, we find orbital periods of 33.6, 37.3, and 36.9 minutes for ZTF 1946+3203, ZTF 0640+1738, and ZTF 0643+0318…

We report additional photometric CCD observations of KPD 0422+5421, a binary with an orbital period of 2.16 hours which contains a subdwarf B star (sdB) and a white dwarf. There are two main results of this work. First, the light curve of…

Context. We present time-resolved spectroscopy and photometry of HS 0218+3229, a new long-period cataclysmic variable discovered within the Hamburg Quasar Survey. It is one of the few systems that allow a dynamical measurement of the masses…

We present here the detection of a brown dwarf orbiting the A9V star HD180777. The radial velocity measurements, obtained with the ELODIE echelle spectrograph at the Haute-Provence Observatory, show a main variation with a period of 28.4…

Among the competing evolution theories for subdwarf-B (sdB) stars is the binary evolution scenario. EC~20117-4014 (=V4640~Sgr) is a spectroscopic binary system consisting of a pulsating sdB star and a late F main-sequence companion…

The white dwarf LHS 3236 (WD1639+153) is shown to be a double-degenerate binary, with each component having a high mass. Astrometry at the U.S. Naval Observatory gives a parallax and distance of 30.86 +/- 0.25 pc and a tangential velocity…

We present results of observations and analysis of five WZ-type dwarf novae: SDSS J080434.20+510349.2, SDSS J102146.44+234926.3, V1108 Her, ASAS J0025 and WZ Sge in 3 - 7 years after their outbursts. We found: 1) the observational evidences…

We report that Kepler Object of Interest 256 (KOI-256) is a mutually eclipsing post-common envelope binary (ePCEB), consisting of a cool white dwarf (M = 0.592 +/- 0.089 MSun, R = 0.01345 +/- 0.00091 RSun, Teff = 7100 +/- 700 K) and an…

We present infrared JHK photometry of the cataclysmic variable SDSS J123813.73-033933.0 (SDSS1238)and analyze it along with optical spectroscopy, demonstrating that the binary system is most probably comprised of a massive white dwarf with…

We present the first results of a dedicated search for pulsating white dwarfs (WDs) in detached white dwarf plus main-sequence binaries. Candidate systems were selected from a catalogue of WD+MS binaries, based on the surface gravities and…

We report the discovery of ZTF J0127+5258, a compact mass-transferring binary with an orbital period of 13.7 minutes. The system contains a white dwarf accretor, which likely originated as a post-common envelope carbon-oxygen (CO) white…

2MASS J05513444+4135297 (herafter J0551+4135) is the only pulsating DAQ white dwarf known with a carbon and hydrogen atmosphere. Its unusual atmospheric composition and kinematics indicate a white dwarf merger origin. We present time-series…

PSR J1528-3146 is a 60.8 ms pulsar orbiting a heavy white dwarf (WD) companion, with an orbital period of 3.18 d. This work aimed at characterizing the pulsar's astrometric, spin and orbital parameters by analyzing timing measurements…

Establishing a large sample of post common envelope binaries (PCEBs) that consist of a white dwarf plus an intermediate mass companion star of spectral type AFGK, offers the potential to provide new constraints on theoretical models of…

We present the discovery of nonradial pulsations in five hot subdwarf B (sdB) stars based on 27 days of nearly continuous time-series photometry using the Kepler spacecraft. We find that every sdB star cooler than $\approx 27\,500\,$K that…

We report the discovery of a transiting brown dwarf companion to KOI-205, a K0 main-sequence star, in a 11.720125-day period orbit. The transits were detected by the Kepler space telescope, and the reflex motion of the star was measured…

A periodic variation in the pulse timings of the pulsating hot subdwarf B star CS 1246 was recently discovered via the O-C diagram and suggests the presence of a binary companion with an orbital period of two weeks. Fits to this phase…

Common-envelope evolution (CEE) is among the most uncertain phases in binary evolution. To empirically constrain CEE, we construct a uniformly selected sample of eclipsing post--common-envelope binaries (PCEBs). Starting from an unresolved…

We report the detection of eclipses in LSPM J1112+7626, which we find to be a moderately bright (I_C = 12.14 +/- 0.05) very low-mass binary system with an orbital period of 41.03236 +/- 0.00002 days, and component masses M_1 = 0.395 +/-…

Accreting magnetic white dwarfs offer an opportunity to understand the interplay between spin-up and spin-down torques in binary systems. Monitoring of the white dwarf spin may reveal whether the white dwarf spin is currently in a state of…