Related papers: A Search for Planets in the Old Open Cluster NGC 6…
We report the results of a search for variable stars in the open cluster NGC 2141. Ten variable stars are detected, among which nine are new variable stars and they are classified as three short period W UMa type eclipsing binaries, two EA…
The Transiting Exoplanet Survey Satellite (TESS) is providing precise time-series photometry for most star clusters in the solar neighborhood. Using the TESS images, we have begun a Cluster Difference Imaging Photometric Survey (CDIPS), in…
The first transiting extrasolar planet, orbiting HD209458, was a Doppler wobble planet before its transits were discovered with a 10 cm CCD camera. Wide-angle CCD cameras, by monitoring in parallel the light curves of tens of thousands of…
We used the 0.5-m robotic telescopes located at the Special Astrophysical Observatory of the Russian Academy of Sciences for monitoring two square degrees of the sky with the aim of detecting new exoplanets. A dimming of the visible…
Late-type stars are known to host numerous exoplanets, and their photometric variability, primarily caused by rotational modulation, provides a unique opportunity to study starspots. As exoplanets transit in front of their host stars, they…
Models of stellar structure and evolution can be constrained by measuring accurate parameters of detached eclipsing binaries in open clusters. Multiple binary stars provide the means to determine helium abundances in these old stellar…
We present 35 new spectroscopic-binary orbits from our extended radial-velocity (RV) survey of the old ($6.4 \pm 0.2$ Gyr) open cluster NGC 188. Using data from the WIYN Open Cluster Study (WOCS) and APOGEE-2, this work nearly doubles the…
We perform a systematic search for atmospheric variability in short-period gas-giant planets (hot Jupiters) observed by the Kepler mission, by looking for temporal variability of their secondary eclipse depths. This is motivated by a recent…
We have made a comprehensive transit search for exoplanets down to about 2 Earth radii in the HD 209458 system, based on nearly uninterrupted broadband optical photometry obtained with the MOST (Microvariability and Oscillations of Stars)…
With more than 80 transits observed in the CoRoT light curve with a cadence of 32 s, CoRoT-Exo-2b provides an excellent case to search for the secondary eclipse of the planet, with an expected signal of less than 10^-4 in relative flux. The…
We have discovered a young M star of mass $0.16\,M_\odot$ and radius $0.63\,R_\odot$, likely in the Upper Sco Association, that exhibits only a single $80\%$ deep occultation of 1-day duration. The star has frequent flares and a…
We present the results of a photometric survey for variable stars in the field of the nearby globular cluster NGC 6752. The cluster was monitored in 1996 and 1997 for a total of 54 hours with 3 different CCD cameras mounted on the 1.0-m…
We report our investigation of the first transiting planet candidate from the YETI project in the young (~4 Myr old) open cluster Trumpler 37. The transit-like signal detected in the lightcurve of the F8V star 2M21385603+5711345 repeats…
We visually inspected the light curves of 7557 Kepler Objects of Interest (KOIs) to search for single transit events (STEs) possibly due to long-period giant planets. We identified 28 STEs in 24 KOIs, among which 14 events are newly…
The primary difficulty with using transits to discover extrasolar planets is the low probability a planet has of transiting its parent star. One way of overcoming this difficulty is to search for transits in dense stellar fields, such as…
Open clusters are fundamental laboratories for investigating stellar and Galactic evolution, and serve as important benchmarks for asteroseismic analyses. Using a boutique method to analyze TESS photometry, we study red giants in two old…
We analyze ultraviolet (~1500 A) images of the old open clusters M67, NGC 188, and NGC 6791 obtained with Ultraviolet Imaging Telescope (UIT) during the second flight of the Astro observatory in March 1995. Twenty stars are detected on the…
Using the Southeastern Association for Research in Astronomy 0.6 meter telescope located at Cerro Tololo, we searched for variable stars in the southern globular cluster NGC 6584. We obtained images during 8 nights between 28 May and 6 July…
Transiting planets around young stars are hard to find due to the enhanced stellar activity. Only a few transiting planets have been detected around stars younger than 100 Myr. We initially detected a transit-like signal in the K2 light…
We present new observations of the cataclysmic variable V523 Lyr, a member of the open cluster NGC 6791. The Kepler Space telescope obtained photometric observations of this source and we examine the nearly 3 year long light curve. The…