Related papers: Detection of Stars within $\sim$0.8 arcseconds of …
We used the Robo-AO laser adaptive optics system to image 99 main sequence and subgiant stars that have Kepler-detected asteroseismic signals. Robo-AO allows us to resolve blended secondary sources at separations as close as 0.15" that may…
Transit search programs such as CoRoT and Kepler now have the capability of detecting planets as small as the Earth. The detection of these planets however requires the removal of all false positives. Although many false positives can be…
Direct imaging in the infrared at the diffraction limit of large telescopes is a unique probe of the properties of young planetary systems. We survey 55 single class I and class II stars in Taurus in the L' filter using natural and laser…
We present high-resolution observations of a sample of 75 K2 targets from Campaigns 1-3 using speckle interferometry on the Southern Astrophysical Research (SOAR) telescope and adaptive optics (AO) imaging at the Keck II telescope. The…
Accurate stellar parameters and precise elemental abundances are vital pieces to correctly characterize discovered planetary systems, better understand planet formation, and trace galactic chemical evolution. We have performed a uniform…
We present the results of an all-sky survey made with the Fine Guidance Sensor on Hubble Space Telescope to search for angularly resolved binary systems among the massive stars. The sample of 224 stars is comprised mainly of Galactic O- and…
Recent high-contrast imaging surveys, looking for planets in young, nearby systems showed evidence of a small number of giant planets at relatively large separation beyond typically 20 au where those surveys are the most sensitive. Access…
We propose a complete framework for the detection, astrometry, and photometry of faint companions from a sequence of adaptive optics corrected short exposures. The algorithms exploit the difference in statistics between the on-axis and…
It is well established that roughly half of all nearby solar-type stars have at least one companion. Stellar companions can have significant implications for the detection and characterization of exoplanets, including triggering false…
We present the results of a speckle interferometric survey of Galactic massive stars that complements and expands upon a similar survey made over a decade ago. The speckle observations were made with the KPNO and CTIO 4 m telescopes and…
High resolution imaging is an important tool for follow-up study of exoplanet candidates found via transit detection with the Kepler Mission. We discuss here HST imaging with the WFC3 of 23 stars that host particularly interesting Kepler…
A large number of direct imaging surveys for exoplanets have been performed in recent years, yielding the first directly imaged planets and providing constraints on the prevalence and distribution of wide planetary systems. However, like…
While radial velocity surveys have demonstrated that the population of gas giants peaks around $3~\text{au}$, the most recent high-contrast imaging surveys have only been sensitive to planets beyond $\sim~10~\text{au}$. Sensitivity at small…
We present preliminary results of an imaging survey for companions to low-luminosity dwarfs with spectral types ranging from M7 to L9. A K-band study with the Near Infrared Camera (NIRC) at the Keck telescope discriminates against…
This year, a second generation of coronagraphs dedicated to high-contrast direct imaging of exoplanets is starting operations. Among them, SPHERE, installed at the focus of the UT3 Very Large Telescope, reaches unprecedented contrast ratios…
The Kepler space telescope observed over 15,000 stars for asteroseismic studies. Of these, 75% of dwarfs (and 8% of giants) were found to show anomalous behavior: such as suppressed oscillations (low amplitude) or no oscillations at all.…
High-precision time series photometry with the Kepler satellite has been crucial to our understanding both of exoplanets, and via asteroseismology, of stellar physics. After the failure of two reaction wheels, the Kepler satellite has been…
Observations of very low-mass stars with Kepler represent an excellent opportunity to search for planetary transits and to characterize optical photometric variability at the cool end of the stellar mass distribution. In this paper, we…
Surveys of nearby field stars indicate that stellar binaries are common, yet little is known about the effects that these companions may have on planet formation and evolution. The Friends of Hot Jupiters project uses three complementary…
This paper presents a new strategy for observing faint galaxies with high order natural guide star systems. We have imaged 5 high galactic latitude fields within the isoplanatic patch of bright stars (8.5 < R < 10.3 mag). The fields provide…