Related papers: Mitigating stellar activity jitter with different …
Context. Searching for extrasolar planets through radial velocity measurements relies on the stability of stellar photospheres. Aims. We aim at characterizing the statistical properties of magnetic activity cycles, and studying their impact…
Stellar activity influences radial velocity (RV) measurements and can also mimic the presence of orbiting planets. As part of the search for planets around the components of wide binaries performed with the SARG High Resolution Spectrograph…
Red Dwarfs (RDs) are the most common, low-mass stars (<=0.5 M_sun) in the Solar neighbourhood, and probably in the Universe as well. Most (likely all) young RDs are magnetically active, and therefore it is impossible to measure their radial…
We present an analysis of the publicly available HARPS radial velocity (RV) measurements for Alpha Cen B, a star hosting an Earth-mass planet candidate in a 3.24 day orbit. The goal is to devise robust ways of extracting low-amplitude RV…
Through the McDonald Observatory M Dwarf Planet Search, we have acquired nearly 3,000 high-resolution spectra of 93 late-type (K5-M5) stars over more than a decade using HET/HRS. This sample provides a unique opportunity to investigate the…
New discoveries of transiting extrasolar planets are reported weekly. Ground based surveys as well as space borne observatories like CoRoT and Kepler are responsible for filling the statistical voids of planets on distant stellar systems. I…
For solar-type stars, spots and their associated magnetic regions induce radial velocity perturbations through the Doppler rotation signal and the suppression of convective blueshift -- collectively known as rotation-modulation. We…
The Kepler mission has been providing high-quality photometric data leading to many breakthroughs in the exoplanet search and in stellar physics. Stellar magnetic activity results from the interaction between rotation, convection, and…
Context. Planetary companions of a fixed mass induce larger amplitude reflex motions around lower-mass stars, which helps make M dwarfs excellent targets for extra-solar planet searches. State of the art velocimeters with $\sim$1m/s…
Planetary debris is observed in the atmospheres of over 1,000 white dwarfs, and two white dwarfs are now observed to contain orbiting minor planets. Exoasteroids and planetary core fragments achieve orbits close to the white dwarf through…
Searches are under way in Advanced LIGO and Virgo data for persistent gravitational waves from continuous sources, e.g. rapidly rotating galactic neutron stars, and stochastic sources, e.g. relic gravitational waves from the Big Bang or…
One of the most powerful methods used to estimate sky-projected spin-orbit angles of exoplanetary systems is through a spectroscopic transit observation known as the Rossiter-McLaughlin (RM) effect. So far mostly single RM observations have…
Context. The high number of super-Earth and Earth-like planets in the habitable zone (HZ) detected around M-dwarf stars in the last years has revealed these stellar objects to be the key for planetary radial velocity (RV) searches. Aims.…
Time-varying inhomogeneities on stellar surfaces constitute one of the largest sources of radial velocity (RV) error for planet detection and characterization. We show that stellar variations, because they manifest on coherent, rotating…
Removing the aberrations introduced by the Point Spread Function (PSF) is a fundamental aspect of astronomical image processing. The presence of noise in observed images makes deconvolution a nontrivial task that necessitates the use of…
Context. The rotation period of stars is an important parameter along with mass, radius, effective temperature. It is an essential parameter for any radial velocity monitoring, as stellar activity can mimic the presence of a planet at the…
We present an in-depth analysis of stellar activity and its effects on radial velocity (RV) for the M2 dwarf GJ 176 based on spectra taken over 10 years from the High Resolution Spectrograph on the Hobby-Eberly Telescope. These data are…
High-precision radial velocity (RV) measurements are crucial for exoplanet detection and characterisation. Efforts to achieve ~10 cm/s precision have been made over the recent decades, with significant advancements in instrumentation, data…
The population of radio-loud stars has to date been studied primarily through either targeted observations of a small number of highly active stars or widefield, single-epoch surveys that cannot easily distinguish stellar emission from…
Light curves produced by wide-field exoplanet transit surveys such as CoRoT, Kepler, and TESS are affected by sensor-wide systematic noise which is correlated both spatiotemporally and with other instrumental parameters such as photometric…