COROT-7
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros[1] |
| Right ascension | 06h 43m 49.0s[1] |
| Declination | −01° 03′ 46.0″[1] |
| Apparent magnitude (V) | 11.668[1] |
| Characteristics | |
| Spectral type | G9V[1] |
| Astrometry | |
| Radial velocity (Rv) | +31.174 ± 0.0086[1] km/s |
| Distance | 489 ± 65[1] ly (150 ± 20[1] pc) |
| Absolute magnitude (MV) | 5.78[1] |
| Details | |
| Mass | 0.91 ± 0.03[1] M☉ |
| Radius | 0.82 ± 0.04[1] R☉ |
| Surface gravity (log g) | 4.47 ± 0.10[1] cgs |
| Temperature | 5250 ± 60[1] K |
| Metallicity | [M/H] = 0.12 ± 0.06[1] |
| Rotation | ~23 days[2] |
| Rotational velocity (v sin i) | <3.5[1] km/s |
| Age | (1.2–2.3) × 109[1] years |
| Other designations | |
2MASS J06434947-0103468, TYC 4799-1733-1, GSC 04799-01733 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
Coordinates: 
06h 43m 49.0s, −01° 03′ 46.0″
COROT-7 (TYC 4799-1733-1) is a G-type main sequence star, slightly smaller and cooler than the Sun. It has an apparent magnitude 11.67, fainter than Proxima Centauri (mag. 11.05), the nearest star to the Sun. This star is located in the Monoceros constellation.[3]
Location and properties
The star is located in the LRa01 field of view of the COROT spacecraft. It is about 500 light years from earth. According to the project website, this field is in the Monoceros constellation.[3] Published data[4] lists the stellar properties as being a G9V yellow dwarf with a temperature of 5250 K, a radius of about 82% of the Sun and a mass of about 91% of the Sun.[1] But other sources have been known to list it is a (K0V) orange dwarf.[5] 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 ± 0.06. The star is estimated to be about 150 parsecs away and with an age in the range 1.2 – 2.3 billion years, is younger than our own star which has an age of 4.6 billion years.[1] The rotation period of the star, inferred by the lightcurve obtained by COROT, is around 23 days.
Planetary system
The star is reported to be orbited by the super-Earth extrasolar planets COROT-7b and COROT-7c, both discovered in 2009.[2] The existence of a possible third planet COROT-7d, detected in a published study,[6] remains unconfirmed. The discovery of the inner planet was made using the astronomical transit method by the COROT program. CoRoT-7b is notable for its small size.[7]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | from 2.3 to 8.5 M⊕ | 0.0172 ± 0.00029 | 0.853585 ± 0.000024 | 0 | — | 1.58 ± 0.1 R⊕ |
| c | from 8.4 to 13.5[note 1] M⊕ | 0.046 | 3.698 ± 0.003 | 0 | — | — |
| d (unconfirmed) | 16.8[note 2] M⊕ | 0.08 | 9.021 ± 0.019 | 0 | — | — |
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.[2][8]
See also
- COROT—an operational French-led ESA planet-hunting mission spacecraft, launched in 2006
Notes
- ↑ Assuming CoRoT-7b and CoRoT-7c are coplanar orbits.
- ↑ Assuming CoRoT-7b and CoRoT-7d are coplanar orbits.
References
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 A. Léger; D. Rouan; J. Schneider; P. Barge; M. Fridlund; et al. (2009). "Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius" (PDF). Astronomy and Astrophysics. 506: 287–302. arXiv:0908.0241
. Bibcode:2009A&A...506..287L. doi:10.1051/0004-6361/200911933. - 1 2 3 4 Queloz, D.; Bouchy, F.; Moutou, C.; Hatzes, A.; Hebrard, G.; et al. (2009). "The CoRoT-7 planetary system: two orbiting Super-Earths" (PDF). Astronomy and Astrophysics. 506: 303. Bibcode:2009A&A...506..303Q. doi:10.1051/0004-6361/200913096. Also available from exoplanet.eu
- 1 2 Rouan; et al. (February 3, 2009). "CoRoT-exo-7b Has CoRoT discovered the first transiting Super-Earth around a main sequence star?" (PDF). Corot Symposium—Paris. Retrieved 2009-07-05.
- ↑ Bruntt; Deleuil; Fridlund; Alonso; Bouchy; Hatzes; Mayor; Moutou; Queloz (2010). "Improved stellar parameters of CoRoT-7". arXiv:1005.3208 [astro-ph.SR].
- ↑ Jean Schneider. "Star : CoRoT-7". The Extrasolar Planets Encyclopaedia. Retrieved 2009-12-26.
- ↑ Hatzes; Dvorak; Wuchterl; Guterman; Hartmann; Fridlund; Gandolfi; Guenther; Paetzold (2010). "An Investigation into the Radial Velocity Variations of CoRoT-7". arXiv:1006.5476 [astro-ph.SR].
- ↑ "Super-Earth found! The smallest transiting extrasolar planet ever discovered". Paris Observatory. February 2009. Retrieved 2009-02-04.
- ↑ "CoRoT-Exo-7b: Confirming the first transiting rocky planet". Retrieved 2010-08-23.
External links
- Schilling, Govert (2009-02-03). "COROT Finds the Smallest Exoplanet Yet". Sky & Telescope. Retrieved 2009-02-04.