Related papers: Post common envelope binaries from SDSS. IV: SDSSJ…
(Abridged) We report the detection of eclipses in the close white-dwarf - M-dwarf binary star RXJ2130.6+4710. We estimate that the spectral type of the M-dwarf is M3.5Ve or M4Ve. We estimate that the effective temperature of the white dwarf…
We report the discovery of KELT J041621-620046, a moderately bright (J$\sim$10.2) M dwarf eclipsing binary system at a distance of 39$\pm$3 pc. KELT J041621-620046 was first identified as an eclipsing binary using observations from the…
We present VLT and Magellan spectroscopy and NTT photometry of nine faint cataclysmic variables (CVs) which were spectroscopically identified by the SDSS. We measure orbital periods for five of these from the velocity variations of the…
Hot subdwarf B stars (sdBs) are extreme horizontal branch stars believed to originate from close binary evolution. Indeed about half of the known sdB stars are found in close binaries with periods ranging from a few hours to a few days. The…
Optical time series photometry of the short period magnetic white dwarf + probable brown dwarf binary SDSS 121209.31+013627.7 reveals pulse-like variability in all bands from i' to u', peaking at u'. These modulations are most likely due to…
We present the reanalysis of three 15 micron JWST/MIRI secondary eclipses of LHS 1140 c, a warm super-Earth (R$_{\rm{p}}$ = 1.272 R$_{\oplus}$) in a 3.78-day orbit around an M4.5 dwarf. We present a novel method for data reduction that…
Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that are theorized to lead to Type Ia supernovae and are also used to gain insight into complex processes involved in stellar binary evolution. We report the…
In this Letter we explore the hypothesis that the quasar SDSSJ092712.65+294344.0 is hosting a massive black hole binary embedded in a circumbinary disc. The lightest, secondary black hole is active, and gas orbiting around it is responsible…
We present phase-resolved spectroscopy of two new short period low accretion rate magnetic binaries, SDSSJ125044.42+154957.3 (Porb = 86 min) and SDSSJ151415.65+074446.5 (Porb = 89 min). Both systems were previously identified as magnetic…
We present time-resolved spectroscopy and photometry of the cataclysmic variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in the Sloan Digital Sky Survey Data Release 4. The orbital period determined from radial…
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 +/-…
The eclipsing binary system 2M 1938+4603 consists of a pulsating hot subdwarf B star and a cool M dwarf companion in an effectively circular three-hour orbit. The light curve shows both primary and secondary eclipses, along with a strong…
We report the discovery of a relatively bright eclipsing binary system, which consists of a white dwarf and a main sequence K7 star with clear signs of chromospheric and spot activity. The light curve of this system shows $\sim0.2$mag…
SDSS 1355+0856 was identified as a hot white dwarf (WD) with a binary companion from time-resolved SDSS spectroscopy as part of the ongoing SWARMS survey. Follow-up observations with the ARC 3.5m telescope and the MMT revealed weak emission…
We present observations and analyses of five little-studied cataclysmic binary stars in the southern celestial hemisphere. Our new observations are from the South African Astronomical Observatory. The objects and salient results are as…
SDSS J1507+52 is an eclipsing cataclysmic variable consisting of a cool, non-radially pulsating white dwarf and an unusually small sub-stellar secondary. The system has a high space velocity and a very short orbital period of about 67…
New spectroscopic observations of the halo hyper-velocity star candidate SDSS J121150.27+143716.2 ($V=17.92$ mag) revealed a cool companion to the hot subdwarf primary. The components have a very similar radial velocity and their absolute…
We report the discovery of an eclipsing binary - HS 0705+6700 - being an sdB star with a faint companion. From its light curve the orbital period of 8263.87 s, the mass ratio of the system q = 0.28, the inclination of 84.4 deg and other…
In a systematic search for eclipsing white dwarfs using Zwicky transient facility (ZTF) data, we found seven eclipsing double white dwarfs with orbital periods ranging from 45 minutes to 3 hours. We collected high-speed light curves,…
We identify SDSS J010657.39-100003.3 (hereafter J0106-1000) as the shortest period detached binary white dwarf (WD) system currently known. We targeted J0106-1000 as part of our radial velocity program to search for companions around known…