Kepler-10
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 19h 02m 43.0612s[1] |
| Declination | +50° 14′ 28.701″[1] |
| Apparent magnitude (V) | 11.157[2] |
| Astrometry | |
| Proper motion (μ) | RA: −18.394±0.045[1] mas/yr Dec.: 41.448±0.046[1] mas/yr |
| Parallax (π) | 5.3618 ± 0.0233[1] mas |
| Distance | 608 ± 3 ly (186.5 ± 0.8 pc) |
| Characteristics | |
| Spectral type | G2V[3] |
| Details | |
| Mass | 0.910 ± 0.021[2] M☉ |
| Radius | 1.065 ± 0.009[2] R☉ |
| Temperature | 5708 ± 28[2] K |
| Age | 10.6+1.5 −1.3[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| KIC | data |
Kepler-10, formerly known as KOI-72, is a Sun-like star in the constellation of Draco that lies 187 parsecs (608 light years) from Earth. Kepler-10 was targeted by NASA's Kepler spacecraft, as it was seen as the first star identified by the Kepler mission that could be a possible host to a small, transiting exoplanet.[4] The star is slightly less massive, slightly larger, and slightly cooler than the Sun; at an estimated 10.4 billion years in age, Kepler-10 is almost 2.6 times the age of the Sun. Kepler-10 is host to a planetary system made up of at least two planets. Kepler-10b, the first undeniably rocky planet,[4] was discovered in its orbit after eight months of observation and announced on January 10, 2011. The planet orbits its star closely, completing an orbit every 0.8 days,[5] and has a density similar to that of iron.[4] The second planet, Kepler-10c, was confirmed on May 23, 2011, based on follow-up observations by the Spitzer Space Telescope. The data shows it has an orbital period of 42.3 days and has a radius more than double that of Earth, but a higher density, making it the largest and most massive rocky planet discovered as of June 2014.[2][6][7]
Nomenclature and history[]
Kepler-10 was named because it was the tenth planetary system observed by the Kepler spacecraft, a NASA satellite designed to search for Earth-like planets that transit, or cross in front of, their host stars with respect to Earth. The transit slightly dims the host star; this periodic dimming effect is then noted by Kepler.[8] After eight months of observation ranging from May 2009 to January 2010, the Kepler team established Kepler-10b as the first rocky exoplanet discovered by the Kepler satellite. Kepler-10 was the first Kepler-targeted star suspected of having a small planet in orbit. Because of that, verifying Kepler's discovery was prioritized by telescopes at the W.M. Keck Observatory in Hawaii. The discovery was successfully verified.[4] Although there had been many potentially rocky exoplanets discovered in the past, Kepler-10b was the first definitively rocky planet to have been discovered.[9]
The discovery of Kepler-10b was announced to the public at a winter meeting of the American Astronomical Society on January 10, 2011 in Seattle.[9] On May 23, 2011, the existence of Kepler-10c was confirmed at the 218th AAS meeting in Boston.[10]
Characteristics[]
Kepler-10 is a G-type star, like the Sun. With a mass of 0.895 (± 0.06) Msun and a radius of 1.056 (± 0.021) Rsun, the star is approximately 10% less massive than and 5% wider than the Sun. The metallicity of Kepler-10, as measured in [Fe/H] (the amount of iron in the star), is -0.15 (± 0.04); this means that Kepler-10 is about 70% as metal-rich as the Sun. Metallicity tends to play a large role in the formation of planets, determining if they form, and what kind of planet they will form.[11] In addition, Kepler-10 is estimated to be 11.9 billion years old and to have an effective temperature of 5627 (± 44) K;[12] To compare, the Sun is younger and hotter, with an age of 4.6 billion years[13] and an effective temperature of 5778 K.[14]
Kepler-10 is located at a distance of 173 (± 27) parsecs from the Earth, which equates to approximately 564 light years. Also, Kepler-10's apparent magnitude, or brightness as seen from Earth, is 10.96; it therefore cannot be seen with the naked eye.[12]
Planetary system[]
Per the usual exoplanet nomenclature, the first planet discovered to be orbiting Kepler-10 is called Kepler-10b. Announced in 2011, it was the first rocky planet identified outside the Solar system. The planet has a mass that is 3.33±0.49 times that of Earth's and a radius that is 1.47+0.03
−0.02 times that of Earth.[2] The planet orbits Kepler-10 at a distance of 0.01684 AU every 0.8375 days; this can be compared to the orbit and orbital period of planet Mercury, which circles the Sun at a distance of 0.3871 AU every 87.97 days.[15] Because the planet orbits so closely to its star, its eccentricity is virtually zero. It, thus, has an extremely circular orbit.[5]
Kepler-10c[6] was also discovered by NASA's Kepler Mission,[16] the second exoplanet found to orbit Kepler-10. Radial-velocity measurements of the body suggest that it has a mass of 17.2±1.9 Earth masses and a radius of 2.35 Earth radii, making it the largest known rocky planet as of 2014. Kepler-10c would orbit Kepler-10 at a distance of 0.24 AU every 45.29 days.[2]
Kepler-10d was discovered in 2017 and still has not been confirmed. It would orbit its parent star at a distance of 0.366 AU every 102±1 days. [17]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 3.33±0.49 M
|