An improved method for estimating the masses of stars with transiting planets

B. Enoch, A. Collier Cameron, N. R. Parley, L. Hebb

Research output: Contribution to journalArticle

88 Citations (Scopus)

Abstract

Context. To determine the physical parameters of a transiting planet and its host star from photometric and spectroscopic analysis, it is essential to independently measure the stellar mass. This is often achieved by the use of evolutionary tracks and isochrones, but the mass result is only as reliable as the models used. Aims. The recent paper by Torres et al. (2010, A&ARv, 18, 67) showed that accurate values for stellar masses and radii could be obtained from a calibration using Teff, log g and [Fe/H]. We investigate whether a similarly good calibration can be obtained by substituting log ρ-the fundamental parameter measured for the host star of a transiting planet-for log g, and apply this to star-exoplanet systems. Methods. We perform a polynomial fit to stellar binary data provided in Torres et al. (2010) to obtain the stellar mass and radius as functions of Teff, log ρ and [Fe/H], with uncertainties on the fit produced from a Monte Carlo analysis. We apply the resulting equations to measurements for seventeen SuperWASP host stars, and also demonstrate the application of the calibration in a Markov Chain Monte Carlo analysis to obtain accurate system parameters where spectroscopic estimates of effective stellar temperature and metallicity are available. Results. We show that the calibration using log ρ produces accurate values for the stellar masses and radii; we obtain masses and radii of the SuperWASP stars in good agreement with isochrone analysis results. We ascertain that the mass calibration is robust against uncertainties resulting from poor photometry, although a good estimate of stellar radius requires good-quality transit light curve to determine the duration of ingress and egress.

Original languageEnglish
Article numberA33
JournalAstronomy and Astrophysics
Volume516
Issue number18
Publication statusPublished - 1 Jun 2010
Externally publishedYes

Fingerprint

planets
stellar mass
estimating
planet
stars
radii
calibration
Monte Carlo analysis
stellar temperature
egress
binary data
Markov chains
spectroscopic analysis
extrasolar planets
estimates
transit
light curve
metallicity
photometry
polynomials

Keywords

  • planetary systems

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Enoch, B., Collier Cameron, A., Parley, N. R., & Hebb, L. (2010). An improved method for estimating the masses of stars with transiting planets. Astronomy and Astrophysics, 516(18), [A33].

An improved method for estimating the masses of stars with transiting planets. / Enoch, B.; Collier Cameron, A.; Parley, N. R.; Hebb, L.

In: Astronomy and Astrophysics, Vol. 516, No. 18, A33, 01.06.2010.

Research output: Contribution to journalArticle

Enoch, B, Collier Cameron, A, Parley, NR & Hebb, L 2010, 'An improved method for estimating the masses of stars with transiting planets', Astronomy and Astrophysics, vol. 516, no. 18, A33.
Enoch B, Collier Cameron A, Parley NR, Hebb L. An improved method for estimating the masses of stars with transiting planets. Astronomy and Astrophysics. 2010 Jun 1;516(18). A33.
Enoch, B. ; Collier Cameron, A. ; Parley, N. R. ; Hebb, L. / An improved method for estimating the masses of stars with transiting planets. In: Astronomy and Astrophysics. 2010 ; Vol. 516, No. 18.
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