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Related papers: Modeling the RV and BVS of active stars

200 papers

Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-meter per second accuracy, the detection of low-mass planets is still very challenging. The rotational modulation and evolution of spots and/or…

Earth and Planetary Astrophysics · Physics 2024-01-12 Haochuan Yu , Suzanne Aigrain , Baptiste Klein , Oscar Barragán , Annelies Mortier , Niamh K. O'Sullivan , Michael Cretignier

We introduce our Radial Velocity Survey for Planets around Young stars (RVSPY), characterise our target stars, and search for substellar companions at orbital separations smaller than a few au from the host star. We use the FEROS…

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…

Solar and Stellar Astrophysics · Physics 2024-11-08 Lily L. Zhao , Megan E. Bedell , David W. Hogg , Rodrigo Luger

We cross-match the GALEX and Kepler surveys to create a unique dataset with both ultraviolet (UV) measurements and highly precise photometric variability measurements in the visible light spectrum. As stellar activity is driven by magnetic…

Earth and Planetary Astrophysics · Physics 2015-06-17 H. M. Cegla , K. G. Stassun , C. A. Watson , F. A. Bastien , J. Pepper

Motivated by recent discussions, both in private and in the literature, we use a Monte Carlo simulation of planetary systems to investigate sources of bias in determining the mass-radius distribution of exoplanets for the two primary…

Earth and Planetary Astrophysics · Physics 2016-02-03 Jason H. Steffen

Context. Radial velocities (RVs) of stars contain both the Doppler reflex motion of potential planetary companions and the drowning and sometimes imitating effect of stellar activity. To separate the two, previous efforts have sought for…

Solar and Stellar Astrophysics · Physics 2023-12-19 K. Al Moulla , X. Dumusque , M. Cretignier

We compare stellar photometric variability, as measured from Kepler light curves by Basri et al. (2011), with measurements of radial velocity (RV) root-mean-square (RMS) variations of all California Planet Search overlap stars. We newly…

Stars show various amounts of radial velocity (RV) jitter due to varying stellar activity levels. The typical amount of RV jitter as a function of stellar age and observational timescale has not yet been systematically quantified, although…

Earth and Planetary Astrophysics · Physics 2019-11-28 Stefan S. Brems , Martin Kürster , Trifon Trifonov , Sabine Reffert , Andreas Quirrenbach

High precision radial velocity (RV) measurements have been central in the study of exoplanets during the last two decades, from the early discovery of hot Jupiters, to the recent mass measurements of Earth-sized planets uncovered by transit…

Instrumentation and Methods for Astrophysics · Physics 2018-05-02 Étienne Artigau , Lison Malo , René Doyon , Pedro Figueira , Xavier Delfosse , Nicola Astudillo-Defru

Stellar activity, such as starspots, can induce radial velocity (RV) variations that can mask or even mimic the RV signature of orbiting exoplanets. For this reason RV exoplanet surveys have been unsuccessful when searching for planets…

Earth and Planetary Astrophysics · Physics 2015-06-12 V. E. Moulds , C. A. Watson , X. Bonfils , S. P. Littlefair , E. K. Simpson

Stellar radial velocity (RV) measurements have proven to be a very successful method for detecting extrasolar planets. Analysing RV data to determine the parameters of the extrasolar planets is a significant statistical challenge owing to…

Earth and Planetary Astrophysics · Physics 2011-08-25 F. Feroz , S. T. Balan , M. P. Hobson

The role of radial velocity (RV) jitter in extrasolar planet search surveys is discussed. Based on the maximum likelihood principle, improved statistical algorithms for RV fitting and period search are developed. These algorithms…

Astrophysics · Physics 2009-02-14 Roman V. Baluev

The measurement of exoplanet masses using the radial velocity (RV) technique is currently limited by stellar activity, which introduces quasiperiodic variability signals that must be modeled and removed to enhance the sensitivity of the RV…

Stellar variability is a key obstacle in reaching the sensitivity required to recover Earth-like exoplanetary signals using the radial velocity (RV) detection method. To explore activity signatures in Sun-like stars, we present SolAster, a…

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…

Twenty-four years after the discoveries of the first exoplanets, the radial-velocity (RV) method is still one of the most productive techniques to detect and confirm exoplanets. But stellar magnetic activity can induce RV variations large…

Stellar active regions, including spots and faculae, can create radial velocity (RV) signals that interfere with the detection and mass measurements of low mass exoplanets. In doing so, these active regions affect each spectral line…

Earth and Planetary Astrophysics · Physics 2022-05-18 Alexander Wise , Peter Plavchan , Xavier Dumusque , Heather Cegla , Duncan Wright

We present a deep-learning based approach for measuring small planetary radial velocities in the presence of stellar variability. We use neural networks to reduce stellar RV jitter in three years of HARPS-N sun-as-a-star spectra. We develop…

Earth and Planetary Astrophysics · Physics 2023-05-10 Ian Colwell , Virisha Timmaraju , Alexander Wise

So far radial velocity (RV) measurements have discovered ~25 stars to host multiple planets. The statistics imply that many of the known hosts of transiting planets should have additional planets, yet none have been solidly detected. They…

Astrophysics · Physics 2009-11-13 Daniel C. Fabrycky

Aims: Stellar activity may complicate the analysis of high-precision radial-velocity spectroscopic data when looking for exoplanets signatures. We aim at quantifying the impact of stellar spots on stars with various spectral types and…

Astrophysics · Physics 2009-11-13 Morgan Desort , Anne-Marie Lagrange , Franck Galland , Stephane Udry , Michel Mayor