Transit light curve and inner structure of close-in planets
Abstract
Planets orbiting very close to their host stars have been found, some of them on the verge of tidal disruption. The ellipsoidal shape of these planets can significantly differ from a sphere, which modifies the transit light curves. Here we present an easy method for taking the effect of the tidal bulge into account in the transit photometric observations. We show that the differences in the light curve are greater than previously thought. When detectable, these differences provide an estimation of the fluid Love number, which is invaluable information on the internal structure of close-in planets. We also derive a simple analytical expression to correct the bulk density of these bodies, that can be 20% smaller than current estimates obtained assuming a spherical radius.
Appendix A is available in electronic form at http://www.aanda.org- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 2014
- DOI:
- 10.1051/0004-6361/201424733
- arXiv:
- arXiv:1410.5495
- Bibcode:
- 2014A&A...570L...5C
- Keywords:
-
- planetary systems;
- techniques: photometric;
- planets and satellites: interiors;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics;
- Physics - Geophysics;
- Physics - Space Physics
- E-Print:
- 6 pages, 3 figures