Related papers: A brown dwarf orbiting around the planetary-nebula…
The light curves of the pre-main-sequence star KH 15D from the years 1913--2003 can be understood if the star is a member of an eccentric binary that is encircled by a vertically thin, inclined ring of dusty gas. Eclipses occur whenever the…
The Kepler Mission has acquired 33.5d of continuous one-minute photometry of KPD 1946+4340, a short-period binary system that consists of an sdB and a white dwarf. In the light curve, eclipses are clearly seen, with the deepest occurring…
The sdB star KPD 0422+5421 was discovered to be a single-lined spectroscopic binary with a period of P=0.0901795 +/- (3\times 10^{-7}) days (2 hours, 10 minutes). The U and B light curves display an ellipsoidal modulation with amplitudes of…
We report photometric observations of the eclipsing close binary CSS21055 (SDSS J141126+200911) that strongly suggest that the companion to the carbon-oxygen white dwarf is a brown dwarf with a mass between 0.030 and 0.074 Msun. The…
We present time-resolved optical spectroscopy of V458 Vulpeculae (Nova Vul 2007 No. 1) spread over a period of 15 months starting 301 days after its discovery. Our data reveal radial velocity variations in the HeII {\lambda}5412 and HeII…
We report the discovery of a young planetary-mass brown dwarf in the rho Oph cloud core. The object was identified as such with the aid of a 1.5-2.4 micron low-resolution spectrum obtained using the NIRC instrument on the Keck I telescope.…
Draco C1 is a known symbiotic binary star system composed of a carbon red giant and a hot, compact companion -- likely a white dwarf -- belonging to the Draco dwarf spheroidal galaxy. From near-infrared spectroscopic observations taken by…
Our aim is to investigate the nature and formation of brown dwarfs by adding a new well-characterised object to the small sample of less than 20 transiting brown dwarfs. One brown dwarf candidate was found by the KESPRINT consortium when…
We searched the orbital period changes in 182 EA-type (including the 101 Algol systems used by \cite{hal89}), 43 EB-type and 53 EW-type binaries with known both the mass ratio and the spectral type of their secondary components. We…
We present new light curves covering 14 to 19 years of observations of four bright proto-planetary nebulae (PPNs), all O-rich and of F spectral type. They each display cyclical light curves with significant variations in amplitude. All four…
We present a new analysis of the multiple star V1200 Centauri based on the most recent observations for this system. We used the photometric observations from the Solaris network and the TESS telescope, combined with the new radial…
In recent years, several close post-common-envelope eclipsing binaries have been found to show cyclic eclipse timing variations (ETVs). This effect is usually interpreted either as the gravitational interaction among circumbinary bodies and…
DV UMa is an eclipsing dwarf nova with an orbital period of $\sim2.06$ h, which lies just at the bottom edge of the period gap. To detect its orbital period changes we present 12 new mid-eclipse times by using our CCD photometric data and…
We present the results of our photoelectric $UBV$ observations of the yellow symbiotic star LT Del over 2010-2018. The binary system LT Del, which consists of a bright K giant and a compact hot star with a temperature of $\sim$100 000 K,…
Multi-color photometric light curves of NO Cam in $V$ $R_C$ and $I_C$ bands are obtained and analyzed simultaneously using the Wilson-Devinney (W-D) program. The solutions suggest that NO Cam is an A-subtype overcontact binary with its mass…
We report the ${\it Kepler}$ photometry of KIC 11401845 displaying multiperiodic pulsations, superimposed on binary effects. Light-curve synthesis represents that the binary star is a short-period detached system with a very low mass ratio…
We report the discovery of a bright (V=11.6 mag) eclipsing hot subdwarf binary of spectral type B with a late main sequence companion from the All Sky Automated Survey (ASAS 102322-3737.0). Such systems are called HW Vir stars after the…
We present high-speed ULTRACAM and SOFI photometry and X-shooter spectroscopy of the recently discovered 94 minute orbital period eclipsing white dwarf / main-sequence binary SDSS J085746.18+034255.3 (CSS 03170) and use these observations…
Eclipsing binaries remain crucial objects for our understanding of the universe. In particular, those that are components of multiple systems can help us solve the problem of the formation of these systems. Analysis of the radial velocities…
In this paper I deal with the WD0137-349 binary system consisting of a white dwarf (WD) and a brown dwarf (BD) in a close circular orbit of about 116 min. I, first, constrain the admissible range of values for the inclination i by noting…