Related papers: The MUCHFUSS photometric campaign
We report on 2MASS J01542930+0053266, a faint eclipsing system composed of two M dwarfs. The variability of this system was originally discovered during a pilot study of the 2MASS Calibration Point Source Working Database. Additional…
We present a catalogue of 1602 white dwarf-main sequence binaries (WDMS) from the spectroscopic Sloan Digital Sky Survey Data Release 6 (SDSS DR6). Among these we identify 440 as new WDMS binaries. We select WDMS binary candidates from…
Approximately 25--50\% of white dwarfs (WDs) exhibit metal absorption lines in their photospheres, interpreted as evidence of ongoing/recent accretion of planetary debris from remnant systems. Previous theoretical studies have suggested…
Stellar evolutionary models predict that most of the early type subdwarf stars in close binary systems have white dwarf companions. More massive companions, such as neutron stars or black holes, are also expected in some cases. The presence…
The magnetic white dwarf SDSS J121209.31+013627.7 exhibits a weak, narrow Halpha emission line whose radial velocity and strength are modulated on a period of ~90 minutes. Though indicative of irradiation on a nearby companion, no cool…
Context. Period variations have been detected in a number of eclipsing close compact binary subdwarf B stars (sdBs) and these have often been interpreted as caused by circumbinary massive planets or brown dwarfs. Various evolutionary…
Brown dwarf companions to white dwarfs are rare, but recent infra-red surveys are slowly reveal- ing examples. We present new observations of the post-common envelope binary WD0137-349, which reveals the effects of irradiation on the ~…
Subdwarf B (sdB) stars are thought to be helium burning stars with low mass hydrogen envelopes. Several evolutionary paths have been proposed to explain the formation of these systems. One of these scenarios is the evolution of the sdB…
In the course of our search for double degenerate binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY) we discovered that the sdB star HE 1047-0436 is radial…
We have used 605 days of photometric data from the Kepler spacecraft to study KIC 6614501, a close binary system with an orbital period of 0.15749747(25) days (3.779939 hours), that consists of a low-mass subdwarf B (sdB) star and a white…
We present here 55 short period PCEBs containing a hot WD and a low-mass MS. Based on the photometric data from ZTF DR19, the light curves are analyzed for about 200 WDMS binaries with emission line(s) identified from SDSS or LAMOST…
We make use of the high photometric precision of Kepler to search for periodic modulations among 14 normal (DA- and DB-type, likely non-magnetic) hot white dwarfs (WDs). In five, and possibly up to seven of the WDs, we detect periodic, ~2…
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…
We report the results of our search for pulsating subdwarf B stars in Full Frame Images, sampled at 30 min cadence and collected during Year 1 of the TESS mission. Year 1 covers most of the southern ecliptic hemisphere. The sample of…
Binaries that contain a hot subdwarf (sdB) star and a main sequence companion may have interacted in the past. This binary population has historically helped determine our understanding of binary stellar evolution. We have computed a grid…
We present the results of a high-resolution imaging survey of 12 brown dwarfs and very low mass stars in the closest (~145 pc) young (~5 Myr) OB association, Upper Scorpius. We obtained images with the Advanced Camera for Surveys/High…
We have obtained high contrast images of four nearby, faint, and very low mass objects 2MASSJ04351455-1414468, SDSSJ044337.61+000205.1, 2MASSJ06085283-2753583 and 2MASSJ06524851-5741376 (here after 2MASS0435-14, SDSS0443+00, 2MASS0608-27…
We present results of a Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed in years 1 and 3 of the TESS mission, during which the southern ecliptic hemisphere was targeted. We…
We have completed a survey of twenty-two ultraviolet-selected hot subdwarfs using the Fiber-fed Extended Range Optical Spectrograph (FEROS) and the 2.2-m telescope at La Silla. The sample includes apparently single objects as well as hot…
We identify SDSSJ121010.1+334722.9 as an eclipsing post-common-envelope binary, with an orbital period of P ~ 3 hrs, containing a very cool, low-mass, DAZ white dwarf and a low-mass main-sequence star of spectral type M5. A model atmosphere…