Related papers: KIC7668647: a 14 day beaming sdB+WD binary with a …

We present the analysis of 200 high-resolution and 150 low-resolution spectra of the pulsating subdwarf close binary KPD 1930+2752 obtained with the Keck and the Calar Alto 2.2 m telescopes. Using metal-rich, line blanketed LTE model…

We present an analysis and interpretation of the Kepler binary system KOI 1224. This is the fourth binary found with Kepler that consists of a thermally bloated, hot white dwarf in a close orbit with a more or less normal star of spectral…

The {\it Kepler} light curve of KIC 4739791 exhibits partial eclipses, inverse O'Connell effect, and multiperiodic pulsations. Including a starspot on either of the binary components, the light-curve synthesis indicates that KIC 4739791 is…

We present the discovery of KIC 9632895b, a 6.2 Earth-radius planet in a low-eccentricity, 240.5-day orbit about an eclipsing binary. The binary itself consists of a 0.93 and 0.194 solar mass pair of stars with an orbital period of 27.3…

Hot subdwarf B stars (sdBs) are core helium-burning stars located on the extreme horizontal branch. About half of the known sdB stars are found in close binaries. Their short orbital periods of 1.2 h to a few days suggest that they are post…

KIC 7177553 was observed by the Kepler satellite to be an eclipsing eccentric binary star system with an 18-day orbital period. Recently, an eclipse timing study of the Kepler binaries has revealed eclipse timing variations in this object…

We report on the results of high dispersion spectroscopy of two `superflare stars', KIC 9766237, and KIC 9944137 with Subaru/HDS. Superflare stars are G-type main sequence stars, but show gigantic flares compared to the Sun, which have been…

About 50% of all known hot subdwarf B stars (sdBs) reside in close (short period) binaries, for which common envelope ejection is the most likely formation mechanism. However, Han et al. 2003 predict that the majority of sdBs should form…

We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD26965, with an orbital period of 42.364$\pm$0.015 days, or alternatively, as the presence of residual,…

Stellar theory enables us to understand the properties of stars at different stages of their evolution, and contributes to other fields of astrophysics such as galactic and exoplanet studies. Assessing the accuracy of stellar theories…

The Kepler spacecraft observed the hot subdwarf star PHL 417 during its extended K2 mission, and the high-precision photometric lightcurve reveals the presence of 17 pulsation modes with periods between 38 and 105 minutes. From follow-up…

We present a preliminary analysis of time series photometry on the pulsating subdwarf B star PG1336-018 acquired as part of two Whole Earth Telescope runs. PG1336-018 is a multi-mode pulsator with at least 15 periods centered around 175…

Stars that are both pulsating and eclipsing offer an important opportunity to better understand many of the physical phenomena that occur in stars, because it is possible to measure the pulsation frequencies of stars for which the masses…

We report the discovery of Kepler-77b (alias KOI-127.01), a Saturn-mass transiting planet in a 3.6-day orbit around a metal-rich solar-like star. We combined the publicly available Kepler photometry (quarters 1-13) with high-resolution…

We confirm a 0.995 d periodic planetary transit-like signal, KOI 6705.01, in the Kepler lightcurve of the star KIC 6423922. Optical and infrared spectra show that this star is a mid M-type dwarf with an effective temperature $= 3327 \pm…

KIC 5359678 is a 6.231-d period F-type eclipsing binary system whose component stars both show starspot activity. It was observed by the Kepler satellite in long cadence for the full four-year duration of the mission. Wang et al (2021)…

We present Kepler photometry and ground based spectroscopy of KIC 4544587, a short-period eccentric eclipsing binary system with self-excited pressure and gravity modes, tidally excited modes, tidally influenced p modes, and rapid apsidal…

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…

Hot subdwarf B (sdB) stars are post-main-sequence stars of high temperature and gravity. Approximately 30$\%$ of sdBs exhibit stable pressure and/or gravity-mode pulsations, which can be used via the timing method to test for companion…

We have discovered a new rapidly oscillating Ap star among the Kepler Mission target stars, KIC 10195926. This star shows two pulsation modes with periods that are amongst the longest known for roAp stars at 17.1 min and 18.1 min,…