COROT-7
Encyclopedia
COROT-7 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.
.It is about 500 light years from earth. According to the project website, this field is in the Monoceros constellation. Published data 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. But other sources have been known to list it is a (K0V) orange dwarf. 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. The rotation period of the star, inferred by the lightcurve obtained by COROT
, is around 23 days.
extrasolar planet
s COROT-7b and COROT-7c
, both discovered in 2009. The existence of a possible third planet COROT-7d, detected in a published study, remain uncomfirmed. 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.
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.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
, slightly smaller and cooler than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. It has an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
11.67, fainter than Proxima Centauri
Proxima Centauri
Proxima Centauri is a red dwarf star about 4.2 light-years distant in the constellation of Centaurus. It was discovered in 1915 by Robert Innes, the Director of the Union Observatory in South Africa, and is the nearest known star to the Sun, although it is too faint to be seen with the naked eye...
(mag. 11.05), the nearest star to the Sun. This star is located in the Monoceros constellation.
Location and properties
The star is located in the LRa01 field of view of the COROT spacecraftCorot
Corot may refer to:* Jean-Baptiste-Camille Corot, French landscape painter * COROT, a space mission with the dual aims of finding extrasolar planets and performing asteroseismology* COROT-7, a dwarf star in the Monoceros constellation...
.It is about 500 light years from earth. According to the project website, this field is in the Monoceros constellation. Published data lists the stellar properties as being a G9V
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
yellow dwarf with a temperature of 5250 K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
, a radius of about 82% of the Sun and a mass of about 91% of the Sun. But other sources have been known to list it is a (K0V) orange dwarf. 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. The rotation period of the star, inferred by the lightcurve obtained by COROT
Corot
Corot may refer to:* Jean-Baptiste-Camille Corot, French landscape painter * COROT, a space mission with the dual aims of finding extrasolar planets and performing asteroseismology* COROT-7, a dwarf star in the Monoceros constellation...
, is around 23 days.
Planetary system
The star is reported to be orbited by the super-EarthSuper-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below the mass of the Solar System's gas giants. The term super-Earth refers only to the mass of the planet, and does not imply anything about the surface conditions or habitability...
extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
s COROT-7b and COROT-7c
COROT-7c
COROT-7c is an extrasolar planet which orbits the G-type main sequence star COROT-7, located approximately 489 light years away in the constellation Monoceros...
, both discovered in 2009. The existence of a possible third planet COROT-7d, detected in a published study, remain uncomfirmed. The discovery of the inner planet was made using the astronomical transit
Astronomical transit
The term transit or astronomical transit has three meanings in astronomy:* A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, hiding a small part of it, as seen by an observer at some particular vantage point...
method by the COROT
Corot
Corot may refer to:* Jean-Baptiste-Camille Corot, French landscape painter * COROT, a space mission with the dual aims of finding extrasolar planets and performing asteroseismology* COROT-7, a dwarf star in the Monoceros constellation...
program. CoRoT-7b is notable for its small size.
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
Radial velocity
Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...
measurements needed to "weigh" the planets.
See also
- COROTCorotCorot may refer to:* Jean-Baptiste-Camille Corot, French landscape painter * COROT, a space mission with the dual aims of finding extrasolar planets and performing asteroseismology* COROT-7, a dwarf star in the Monoceros constellation...
- an operational French-ledCNESThe is the French government space agency . Established under President Charles de Gaulle in 1961, its headquarters are located in central Paris and it is under the supervision of the French Ministries of Defence and Research...
ESA planet-hunting mission spacecraft, launched in 2006