Related papers: A search for brown-dwarf like secondaries in catac…

We have used the PACS instrument on the Herschel Space Observatory to observe eight cataclysmic variables at 70 and 160 microns. Of these eight objects, only AM Her was detected. We have combined the Herschel results with ground-based,…

We present a Roche tomography reconstruction of the secondary star in the cataclysmic variable AE Aqr. The tomogram reveals several surface inhomogeneities that are due to the presence of large, cool starspots. In addition to a number of…

We present a new sample of $K$-band spectral observations for CVs: non-magnetic and magnetic as well as present day and pre CVs. The purpose of this diverse sample is to address the recent claim that the secondary stars in dwarf novae are…

We present a method to select hot subdwarf stars with A to M-type companions using photometric selection criteria. We cover a wide range in wavelength by combining GALEX ultraviolet data, optical photometry from the SDSS and the Carlsberg…

We report observations of the known cataclysmic variable star (CV) V704 And, and also confirm that the optical counterpart of the ROSAT Galactic Plane Survey source RX J2338+431 is a heretofore-neglected CV. Photometric and spectroscopic…

We searched for binary companions to 20 young brown dwarfs in the Upper Scorpius association (145 pc, 5 Myr, nearest OB association) with the the Laser Guide Star adaptive optics system and the facility infrared camera NIRC2 on the 10 m…

We present the complete set of thirty four ASCA observations of non-magnetic cataclysmic variables. Timing analysis reveals large X-ray flux variations in dwarf novae in outburst (Z Cam, SS Cyg and SU UMa) and orbital modulation in high…

CSS1603+19 is a cataclysmic variable (CV) with an orbital period of 81.96 min, near the minimal period of cataclysmic variables. It is unusual in having a strong mid-infrared excess inconsistent with thermal emission from a brown dwarf…

We obtained time-series radial velocity spectroscopy of twenty cataclysmic variable stars, with the aim of determining orbital periods P_orb. All of the stars reported here prove to have P_orb > 3.5 h. For sixteen of the stars, these are…

About a third of the hot subdwarfs of spectral type B, which are mostly core-helium burning objects on the extreme horizontal branch, are found in close binaries with cool, low-mass stellar, substellar, or white dwarf companions. They can…

We present the K-band spectrum of the cataclysmic variable RXJ 0502.8+1624 (Tau 4). The spectrum shows a broad, smooth hump, with no absorption lines from the secondary star visible. This result indicates that the infrared light of this…

Neither standard model SEDs nor truncated standard model SEDs fit observed spectra of QU Carinae with acceptable accuracy over the range 900\AA to 3000\AA. Non-standard model SEDs fit the observation set accurately. The non-standard…

The spectrum of the recently discovered cataclysmic variable star (CV) ASAS-SN 13cl shows that a secondary star with spectral type K4 (+- 2 subclasses) contributes roughly half the optical light. The radial velocities of the secondary are…

The secondary in cataclysmic variables (CV's) is usually detected by cross-correlation of the CV spectrum with that of a K or M dwarf template, to produce a radial velocity curve. Although this method has demonstrated its power, it has its…

We search for stellar and substellar companions of young nearby stars to investigate stellar multiplicity and formation of stellar and substellar companions. We detect common proper-motion companions of stars via multi-epoch imaging. Their…

Context. In the context of a large campaign to determine the system parameters of high mass transfer cataclysmic variables, we found VY Scl in a low state in 2008. Aims. Making use of this low state, we study the stellar components of the…

Determining the presence of widely separated substellar-mass companion is crucial to understand the dynamics of inner planets in extrasolar planetary systems (e.g. to explain their high mean eccentricity as inner planets are perturbed by…

We present a set of Roche tomography reconstructions of the secondary stars in the cataclysmic variables AM Her, QQ Vul, IP Peg and HU Aqr. The image reconstructions show distinct asymmetries in the irradiation pattern for all four systems…

We study a possibility to detect signatures of brown dwarf companions in a circumstellar disc based on spectral energy distributions (SED). We present the results of SED simulations for a system with a 0.8 $M_{\odot}$ central object and a…

We studied the spectral energy distribution (SED) of 22 known AM~CVns with orbital periods ($P_{orb}$) larger than 35~min using multiwavelength public photometric data to estimate the effective temperature of the accreting white dwarf. We…