COROT-7 (also known as TYC 4799-1733-1) is a G-type main-sequence star located about 520 light years away from Earth in the constellation Monoceros. It has an apparent magnitude of 11.67 which is fainter that Proxima Centauri, the closest star to the Sun. The star is slightly smaller and cooler than the Sun.
Characteristics[]
COROT-7 is a G9V yellow dwarf star, with a temperature of 5250 K, although some sources list it as a K0V orange dwarf. The star is located 520 light years from Earth. It is located in the LRa01 field of view of the COROT spacecraft. It has a radius of 82% of the Sun and a mass about 91% that of the Sun. The metallicity, i.e. the quantity [M/H] of the star, which is the base-10 logarithm of the ratio of the star's metal abundance (given by the ratio of metals to hydrogen) to that of the Sun is 0.12. The estimated age of this star is about 1.2 - 2.3 billion years, younger than the Sun at 4.6 billion years. The rotation period of the star is around 23 days.
Planetary system[]
The star is currently confirmed to be orbited by two extrasolar planets, COROT-7b and COROT-7c, which were both discovered in 2009. There may be a third planet in the system, COROT-7d, although it is currently unconfirmed.
| Planet | Mass | Semimajor axis | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ~2.3-8.5 Earth mass | 0.0172 AU | 0.853585 days (20.48 hours) | 0 | 80° | 1.58 Earth radius |
| c | ~8.4-13.5 Earth mass | 0.046 AU | 3.698 days | 0 | N/A | N/A |
| d (unconfirmed) | 16.8 Earth mass | 0.08 AU | 9.021 days | 0 | N/A | N/A |
This star was reported to have stellar activity, making the confirmation process for CoRoT-7b more difficult. In fact, mass estimates are affected by large uncertainty due to stellar activity, that perturbs the radial velocity measurements needed to "weigh" the planets.