An observational correlation between stellar brightness variations and surface gravity

Fabienne A. Bastien, Keivan G. Stassun, Gibor Basri, Joshua Pepper

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

Surface gravity is a basic stellar property, but it is difficult to measure accurately, with typical uncertainties of 25 to 50 per cent if measured spectroscopically and 90 to 150 per cent if measured photometrically. Asteroseismology measures gravity with an uncertainty of about 2 per cent but is restricted to relatively small samples of bright stars, most of which are giants. The availability of high-precision measurements of brightness variations for more than 150,000 stars provides an opportunity to investigate whether the variations can be used to determine surface gravities. The Fourier power of granulation on a star's surface correlates physically with surface gravity: if brightness variations on timescales of hours arise from granulation, then such variations should correlate with surface gravity. Here we report an analysis of archival data that reveals an observational correlation between surface gravity and root mean squared brightness variations on timescales of less than eight hours for stars with temperatures of 4,500 to 6,750 kelvin, log surface gravities of 2.5 to 4.5 (cgs units) and overall brightness variations of less than three parts per thousand. A straightforward observation of optical brightness variations therefore allows a determination of the surface gravity with a precision of better than 25 per cent for inactive Sun-like stars at main-sequence to giant stages of evolution.

Original languageEnglish (US)
Pages (from-to)427-430
Number of pages4
JournalNature
Volume500
Issue number7463
DOIs
StatePublished - Aug 29 2013

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Gravitation
Uncertainty
Solar System
Observation
Temperature

All Science Journal Classification (ASJC) codes

  • General

Cite this

Bastien, Fabienne A. ; Stassun, Keivan G. ; Basri, Gibor ; Pepper, Joshua. / An observational correlation between stellar brightness variations and surface gravity. In: Nature. 2013 ; Vol. 500, No. 7463. pp. 427-430.
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An observational correlation between stellar brightness variations and surface gravity. / Bastien, Fabienne A.; Stassun, Keivan G.; Basri, Gibor; Pepper, Joshua.

In: Nature, Vol. 500, No. 7463, 29.08.2013, p. 427-430.

Research output: Contribution to journalArticle

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