LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS
Abstract
Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale brightness variations ({sup f}licker{sup )} of stars can be used to measure log g to a high accuracy of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 bright (Kepmag < 13) candidate planet-hosting stars with T {sub eff} = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the bright planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.
- Authors:
-
- Physics and Astronomy Department, Vanderbilt University, 1807 Station B, Nashville, TN 37235 (United States)
- Publication Date:
- OSTI Identifier:
- 22365802
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal Letters
- Additional Journal Information:
- Journal Volume: 788; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; BRIGHTNESS; GRAVITATION; MASS; PLANETS; SATELLITES; STAR EVOLUTION; STARS; SURFACES; VARIATIONS
Citation Formats
Bastien, Fabienne A., Stassun, Keivan G., and Pepper, Joshua. LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS. United States: N. p., 2014.
Web. doi:10.1088/2041-8205/788/1/L9.
Bastien, Fabienne A., Stassun, Keivan G., & Pepper, Joshua. LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS. United States. https://doi.org/10.1088/2041-8205/788/1/L9
Bastien, Fabienne A., Stassun, Keivan G., and Pepper, Joshua. 2014.
"LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS". United States. https://doi.org/10.1088/2041-8205/788/1/L9.
@article{osti_22365802,
title = {LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS},
author = {Bastien, Fabienne A. and Stassun, Keivan G. and Pepper, Joshua},
abstractNote = {Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale brightness variations ({sup f}licker{sup )} of stars can be used to measure log g to a high accuracy of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 bright (Kepmag < 13) candidate planet-hosting stars with T {sub eff} = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the bright planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.},
doi = {10.1088/2041-8205/788/1/L9},
url = {https://www.osti.gov/biblio/22365802},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 788,
place = {United States},
year = {Tue Jun 10 00:00:00 EDT 2014},
month = {Tue Jun 10 00:00:00 EDT 2014}
}