Related papers: KIC 7582608: A new Kepler roAp star with frequency…
KIC 10661783 is an eclipsing binary that shows Delta Sct-like oscillations. More than 60 pulsation frequencies have been detected in its light curve as observed by the Kepler satellite. We want to determine the fundamental stellar and…
We analyse 38-month of contiguous short-cadence data, concentrating on mode multiplets induced by the star rotation and on frequencies forming linear combinations that show intriguing behaviors during the course of the observations. We find…
We report the discovery of pulsations in the N-rich PG 1159-type central star of the planetary nebula Kn 61 based on one month of Kepler Short Cadence observations. We detect four significant peaks in the frequency range consistent with…
We present the analysis of 65 hours of high speed photometric observations of HD 12098 taken from State Observatory, Naini Tal and Gurushikhar Observatory, Mt.Abu on sixteen nights spanning from November 1999 to November 2000. HD 12098 is…
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp…
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…
Using data obtained during the RATS-Kepler project we identified one short duration flare in a 1 hour sequence of ground based photometry of the dwarf star KIC 5474065. Observations made using GTC show it is a star with a M4 V spectral…
The rapidly oscillating Ap (roAp) star 10 Aql shows one of the lowest photometric pulsation amplitudes and is characterized by an unusual spectroscopic pulsational behavior compared to other roAp stars. More than 1000 spectra were taken…
We present a new asteroseismic analysis of KIC~6048106, a \textit{Kepler} Algol-type eclipsing binary star in a circularized orbit with $P_\rm{orb}$=1.559361$\pm$0.000036~d. Based on a physical model for the binary and its corresponding set…
KIC 7955301 is a hierarchical triple system with eclipse timing and depth variations discovered by the Kepler mission. It is composed of a non-eclipsing primary star at the bottom of the red giant branch on a 209-day orbit with a K/G-type…
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…
We intensively studied the flare activity on the stellar object KIC011764567. The star was thought to be solar type, with a temperature of $T_{eff} = (5640 \pm 200)\,$K, $\log(g) = (4.3 \pm 0.3)\,$dex and a rotational period of Prot 22 d…
Stellar structure and evolution can be studied in great detail by asteroseismic methods, provided data of high precision are available. We determine the effective temperature (Teff), surface gravity (log g), metallicity, and the projected…
The analysis of eclipsing binaries containing non-radial pulsators allows: i) to combine two different and independent sources of information on the internal structure and evolutionary status of the components, and ii) to study the effects…
The physics of magnetic hot stars and how a large-scale magnetic field affects their interior properties is largely unknown. Few studies have combined high-quality observations and modelling of magnetic pulsating stars, known as…
The high precision data obtained by the {\it Kepler} satellite allows us to detect hybrid type pulsator candidates more accurately than the data obtained by ground-based observations. In this study, we present preliminary results on the new…
We report 33 V-band observations by the Hereford Arizona Observatory (HAO) of the enigmatic star KIC 8462852 during the two week period 3-17 August 2017. We find a striking resemblance of these observations to the Kepler day 1540 dip with…
We present the results of time-series photometric analysis of 15106 A-K type stars observed by the Kepler space mission. We identified 513 new rotational variables and measured their starspot rotation periods as a function of spectral type…
We present the ${\it Kepler}$ photometry of KIC 6048106 exhibiting O'Connell effect and multiperiodic pulsations. Including a starspot on either of the components, light-curve synthesis indicates that this system is a semi-detached Algol…
In recent years it has been claimed that the length of stellar activity cycles is determined by the stellar rotation rate. It is observed that the cycle period increases with rotation period along the so-called active and inactive…