Visibilities and bolometric corrections for stellar oscillation modes observed by Kepler
Abstract
Context.Kepler produces a large amount of data used for asteroseismological analyses, particularly of solar-like stars and red giants. The mode amplitudes observed in the Kepler spectral band have to be converted into bolometric amplitudes to be compared to models.
Aims: We give a simple bolometric correction for the amplitudes of radial modes observed with Kepler, as well as the relative visibilities of non-radial modes.
Methods: We numerically compute the bolometric correction cK-bol and mode visibilities for different effective temperatures Teff within the range 4000-7500 K, using a similar approach to a recent one from the literature.
Results: We derive a law for the correction to bolometric values: cK - bol = 1 + a1(Teff - To) + a2(Teff - To)2, with To = 5934 K, a1 = 1.349 × 10-4 K-1, and a2 = -3.120 × 10-9 K-2 or, alternatively, as the power law cK - bol = (Teff/To)α with α = 0.80. We give tabulated values for the mode visibilities based on limb-darkening (LD), computed from ATLAS9 model atmospheres for Teff ∈ [4000,7500] K, log g ∈ [2.5,4.5] , and [M/H] ∈ [ - 1.0, + 1.0] . We show that using LD profiles already integrated over the spectral band provides quick and good approximations for visibilities. We point out the limits of these classical visibility estimations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 2011
- DOI:
- 10.1051/0004-6361/201016230
- arXiv:
- arXiv:1105.4557
- Bibcode:
- 2011A&A...531A.124B
- Keywords:
-
- asteroseismology;
- stars: atmospheres;
- stars: solar-type;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 5 pages, 4 figures, 1 table, minor language edition. Published in A&