Estimating stellar radial velocity variability from kepler and galex: Implications for the radial velocity confirmation of exoplanets

H. M. Cegla, K. G. Stassun, C. A. Watson, F. A. Bastien, J. Pepper

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

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 field modulations, we have used UV emission from the magnetically heated gas in the stellar atmosphere to serve as our proxy for the more well-known stellar activity indicator, R′ HK . The R′ HK approximations were in turn used to estimate the level of astrophysical noise expected in radial velocity (RV) measurements and these were then searched for correlations with photometric variability. We find significant scatter in our attempts to estimate RV noise for magnetically active stars, which we attribute to variations in the phase and strength of the stellar magnetic cycle that drives the activity of these targets. However, for stars we deem to be magnetically quiet, we do find a clear correlation between photometric variability and estimated levels of RV noise (with variability up to ∼10 m s-1). We conclude that for these quiet stars, we can use photometric measurements as a proxy to estimate the RV noise expected. As a result, the procedure outlined in this paper may help select targets best-suited for RV follow-up necessary for planet confirmation.

Original languageEnglish (US)
Article number104
JournalAstrophysical Journal
Volume780
Issue number1
DOIs
StatePublished - Jan 1 2014

Fingerprint

extrasolar planets
radial velocity
estimating
stellar activity
stars
estimates
stellar atmospheres
ultraviolet emission
velocity measurement
planets
astrophysics
planet
magnetic field
modulation
cycles
atmosphere
approximation
gases
gas
magnetic fields

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

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Estimating stellar radial velocity variability from kepler and galex : Implications for the radial velocity confirmation of exoplanets. / Cegla, H. M.; Stassun, K. G.; Watson, C. A.; Bastien, F. A.; Pepper, J.

In: Astrophysical Journal, Vol. 780, No. 1, 104, 01.01.2014.

Research output: Contribution to journalArticle

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