Related papers: Mitigating astrometric bias in barycentric correct…
Galaxies follow a tight radial acceleration relation (RAR): the acceleration observed at every radius correlates with that expected from the distribution of baryons. We use the Markov Chain Monte Carlo method to fit the mean RAR to 175…
Precise radial velocity (PRV) surveys are important for the search of Earth analogs around nearby bright stars. Such planets induce a small stellar reflex motion with RV amplitude of $\sim$10 cm/s. Detecting such a small RV signal poses…
Astronomical data are typically irregular in time, e.g. the space (HIPPARCOS/TYCHO, KEPLER, GAIA, WISE etc.) and ground-based CCD (NSVS, ASAS, CRTS, SuperWASP etc.) and photographic (Harvard, Sonneberg, Odessa etc.) photometrical surveys.…
Under certain conditions, stellar radial velocities can be determined from astrometry, without any use of spectroscopy. This enables us to identify phenomena, other than the Doppler effect, that are displacing spectral lines. The change of…
Many novel methods have been proposed to mitigate stellar activity for exoplanet detection as the presence of stellar activity in radial velocity (RV) measurements is the current major limitation. Unlike traditional methods that model…
Telluric absorption lines impact measuring precise radial velocities (RVs) from ground-based, high-resolution spectrographs. In this paper, we simulate the dependence of this impact on stellar spectral type and extend the work of the first…
Unresolved stellar companions can cause both under-estimations in the radii of transiting planets and over-estimations of their detectability, affecting our ability to reliably measure planet occurrence rates. To quantify the latter, we…
(Abridged) Aims: Systematic surveys to search for exoplanets have been mostly dedicated to solar-type stars sofar. We developed in 2004 a method to extend such searches to earlier A-F type dwarfs and started spectroscopic surveys to search…
Context. Thanks to more than 20 years of monitoring, the radial velocity (RV) method has detected long-period companions (P > 10yr) around several dozens of stars. Yet, the true nature of these companions remains unclear because of the…
We report on 176 close (<2") stellar companions detected with high-resolution imaging near 170 hosts of Kepler Objects of Interest. These Kepler targets were prioritized for imaging follow-up based on the presence of small planets, so most…
A low-amplitude periodic signal in the radial velocity (RV) time series of Barnard's Star was recently attributed to a planetary companion with a minimum mass of ${\sim}$3.2 $M_\oplus$ at an orbital period of $\sim$233 days. The relatively…
One of the main goals of the COROT mission is to get precise photometric observations of selected bright stars in order to allow the modelling of their interior through asteroseismology. However, in order to interpret the…
We present a technique to extract radial velocity measurements from echelle spectrograph observations of rapidly rotating stars ($V\sin{i} \gtrsim 50$ km s$^{-1}$). This type of measurement is difficult because the line widths of such stars…
The combination of visual and spectroscopic orbits in binary systems enables precise distance measurements without additional assumptions, making them ideal for examining the parallax zero-point offset (PZPO) at bright magnitudes (G < 13)…
Context. The HARPS spectrograph provides state-of-the-art stellar radial velocity (RV) measurements with a precision down to 1 m/s. The spectra are extracted with a dedicated data-reduction software (DRS) and the RVs are computed by CCF…
The current and upcoming high precision photometric surveys such as TESS, CHEOPS, and PLATO will provide the community with thousands of new exoplanet candidates. As a consequence, the presence of such a correlation is crucial in selecting…
Using the adaptive optics facilities at the 200-in Hale and 10-m Keck II, we observed in the near infrared a sample of 12 binary and multiple stars and one open cluster. We used the near diffraction limited images of these systems to…
Astrometric detection and mass determination of Earth-mass exoplanets requires sub-microarcsec accuracy, which is theoretically possible with an imaging space telescope using field stars as an astrometric reference. The measurement must…
Radial velocity searches for extrasolar planets have discovered stars undergoing slow accelerations. The accelerations are likely due to one or more gas giant planets or brown dwarfs orbiting with period longer than the total time span of…
Different stellar phenomena affect radial velocities (RVs), causing variations large enough to make it difficult to identify planet signals from the stellar variability. RV variations caused by stellar oscillations and granulation can be…