Related papers: Exoplanets around G-K Giants
For 6 years the Convection, Rotation, and Planetary Transits (CoRoT) space mission has acquired photometric data from more than one hundred thousand point sources towards and directly opposite from the inner and outer regions of the Galaxy.…
Recent discoveries of transiting giant exoplanets around M-dwarf stars (GEMS), aided by the all-sky coverage of TESS, are starting to stretch theories of planet formation through the core-accretion scenario. Recent upper limits on their…
Our knowledge of the populations and occurrence rates of planets orbiting evolved intermediate-mass stars lags behind that for solar-type stars by at least a decade. Some radial velocity surveys have targeted these low-luminosity giant…
We present the current status of and new results from our search for exoplanets in a sample of solar-mass, evolved stars observed with the HARPS-N and the 3.6-m Telescopio Nazionale Galileo (TNG), and the High Resolution Spectrograph (HRS)…
Stellar activity due to different processes (magnetic activity, photospheric flows) affects the measurement of radial velocities (RV). Radial velocities have been widely used to detect exoplanets, although the stellar signal significantly…
Kepler-444 provides a unique opportunity to probe the atmospheric composition and evolution of a compact system of exoplanets smaller than the Earth. Five planets transit this bright K star at close orbital distances, but they are too small…
Transit and radial velocity surveys have deeply explored the population of extrasolar giant planets, with hundreds of objects detected to date. All these detections allow to understand their physical properties and to constrain their…
The radius valley -- a deficit of exoplanets between super-Earths and sub-Neptunes -- is a key diagnostic of planet formation and atmospheric evolution. We investigate how the radius valley depends on stellar type by analyzing an updated,…
Efforts to discover and characterize habitable zone planets have primarily focused on Sun-like stars and M dwarfs. K stars, however, provide an appealing compromise between these two alternatives that has been relatively unexplored.…
We have carried out a survey of X-ray emission from stars with giant planets, combining both archival and targeted surveys. Over 230 stars have been currently identified as possessing planets, and roughly a third of these have been detected…
We present the results of a 5.5-year CCD photometric campaign that monitored 261 bright, southern, semi-regular variables with relatively precise Hipparcos parallaxes. The data are supplemented with independent photoelectric observations of…
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…
Context. Giant planets play a major role in multiple planetary systems. Knowing their demographics is important to test their overall impact on planetary systems formation. It is also important to test their formation processes. Recently,…
We are studying the influence of stellar multiplicity on exoplanet systems, in particular systems that have been detected via radial-velocity searches. We are in particular interested in the closest companions as they would have a strong…
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…
Before discovering the first exoplanets, the Radial Velocity (RV) method had been used for decades to discover binary stars. Despite significant advancements in this technique, it is limited by the intrinsic mass-inclination degeneracy that…
The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditions under which life could exist elsewhere in our Galaxy.…
(Abridged) The observed radial velocity (RV) eccentricity distribution for extrasolar planets in single-planet systems shows that a significant fraction of planets are eccentric ($e > 0.1$). Here we investigate the effects on an RV planet's…
We analyze the K band luminosities of a sample of galactic long-period variables using parallaxes measured by the Hipparcos mission. The parallaxes are in most cases re-computed from the Hipparcos Intermediate Astrometric Data using…
In the last two decades, thousands of extrasolar planets were discovered based on different observational techniques, and their number must increase substantially in virtue of the ongoing and near-future approved missions and facilities. It…