Flicker as a tool for characterizing planets though asterodensity profiling
Research output: Contribution to journal › Journal article › Research › peer-review
Variability in the time series brightness of a star on a timescale of
8 hr, known as "flicker," has been previously demonstrated to serve as a
proxy for the surface gravity of a star by Bastien et al. Although
surface gravity is crucial for stellar classification, it is the mean
stellar density that is most useful when studying transiting exoplanets,
due to its direct impact on the transit light curve shape. Indeed, an
accurate and independent measure of the stellar density can be leveraged
to infer subtle properties of a transiting system, such as the
companion's orbital eccentricity via asterodensity profiling (AP). We
here calibrate flicker to the mean stellar density of 439 Kepler targets with asteroseismology, allowing us to derive a new empirical relation given by log10(ρ (kg m–3)) = 5.413 – 1.850log10(F 8 (ppm)). The calibration is valid for stars with 4500 < T eff < 6500 K, KP < 14, and flicker estimates corresponding to stars with 3.25 < log g
< 4.43. Our relation has a model error in the stellar density of
31.7% and so has ~8 times lower precision than that from
asteroseismology but is applicable to a sample ~40 times greater.
Flicker therefore provides an empirical method to enable AP on hundreds
of planetary candidates from present and future missions.
Original language | English |
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Article number | L32 |
Journal | The Astrophysical Journal Letters |
Volume | 785 |
Issue number | 2 |
Number of pages | 5 |
ISSN | 2041-8205 |
DOIs | |
Publication status | Published - 20 Apr 2014 |
ID: 140023421