Related papers: The Search for Stellar Companions to Exoplanet Hos…
Roughly half of Solar-type planet hosts have stellar companions, so understanding how these binary companions affect the formation and evolution of planets is an important component to understanding planetary systems overall. Measuring the…
A study of the host stars to exoplanets is important to understanding their environment. To that end, we report new speckle observations of a sample of exoplanet host primaries. The bright exoplanet host HD 8673 (= HIP 6702) is revealed to…
This chapter reviews various methods of detecting planetary companions to stars from an observational perspective, focusing on radial velocities, astrometry, direct imaging, transits, and gravitational microlensing. For each method, this…
We carry out a systematic search campaign for wide companions of exoplanet host stars to study their multiplicity and its influence on the long-term stability and the orbital parameters of the exoplanets. We have already found 6 wide…
Context: Planets outside our solar system transiting their host star, i. e. those with an orbital inclination near 90 degree, are of special interest to derive physical properties of extrasolar planets. With the knowledge of the host star's…
Models are developed to simulate lightcurves of stars dimmed by transiting exoplanets with and without rings. These models are then applied to \textit{Kepler} photometry to search for planetary rings in a sample of 21 exoplanets, mostly hot…
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…
We investigate a new approach to the detection of companions to extrasolar planets beyond the transit method. We discuss the possibility of the existence of binary planets. We develop a method based on the imaging of a planet-companion as…
Both direct and indirect methods of exoplanet detection rely upon detailed knowledge of the potential host stars. Such stellar characterization allows for accurate extraction of planetary properties, as well as contributing to our overall…
Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, are much more promising and have indeed led to the discovery…
Though there are now many hundreds of confirmed exoplanets known, the binarity of exoplanet host stars is not well understood. This is particularly true of host stars which harbor a giant planet in a highly eccentric orbit since these are…
Due to their extremely small luminosity compared to the stars they orbit, planets outside our own Solar System are extraordinarily difficult to detect directly in optical light. Careful photometric monitoring of distant stars, however, can…
We present results of a reconnaissance for stellar companions to all 131 radial-velocity-detected candidate extrasolar planetary systems known as of July 1, 2005. CPM companions were investigated using the multi-epoch DSS images, and…
Exoplanets which are detected using the radial velocity technique have a well-known ambiguity of their true mass, caused by the unknown inclination of the planetary orbit with respect to the plane of the sky. Constraints on the inclination…
For centuries, humanity wondered if there were other worlds like ours in the Universe. For about a quarter of a century, we have known that planetary systems exist around other stars, and more than 3800 exoplanetary systems have been…
Rapid rotation and nonradial pulsations enable Be stars to build decretion disks, where the characteristic line emission forms. A major but unconstrained fraction of Be stars owe their rapid rotation to mass and angular-momentum transfer in…
Ground-based long baseline interferometry is a powerful tool for characterizing exoplanets which are too close to their host star to be imaged with single-dish telescopes. The CHARA Array can resolve companions down to 0.5 milli-arcseconds,…
The sensitivity of radial velocity (RV) surveys for exoplanet detection are extending to increasingly long orbital periods, where companions with periods of several years are now being regularly discovered. Companions with orbital periods…
We present the latest results of an ongoing multiplicity survey of exoplanet hosts, which was initiated at the Astrophysical Institute and University Observatory Jena, using data from the second data release of the ESA-Gaia mission. In this…
The detection of transits is an efficient technique to uncover faint companions around stars. The full characterisation of the companions (M-type stars, brown dwarfs or exoplanets) requires high-resolution spectroscopy to measure properly…