H-activity and ages for stars in the SARG survey
arXiv:1609.04660 · doi:10.1051/0004-6361/201628531
Abstract
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 at the TNG, it was discovered that HD 200466A shows strong variation in RV that is well correlated with the activity index based on H. We used SARG to study the H line variations in each component of the binaries and a few bright stars to test the capability of the H index of revealing the rotation period or activity cycle. We also analysed the relations between the average activity level and other physical properties of the stars. We finally tried to reveal signals in the RVs that are due to the activity. At least in some cases the variation in the observed RVs is due to the stellar activity. We confirm that H can be used as an activity indicator for solar-type stars and as an age indicator for stars younger than 1.5 Gyr.
Accepted by A&A, 14 pages, 13 figures
References in corpus (8)
- The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
- Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
- Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
- Stellar activity of planetary host star HD 189733
- Fluxes in Hαand Ca II H and K for a sample of Southern stars
- Revising the ages of planet-hosting stars
- Line bisectors and radial velocity jitter from SARG spectra
- A vigorous activity cycle mimicking a planetary system in HD200466