BD+20594b
Coordinates: 03h 34m 36.23s, +20° 35′ 57.2″
Exoplanet | List of exoplanets
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Parent star | ||||||
Star | BD+20°594 | |||||
Constellation | Aries | |||||
Right ascension | (α) | 03h 34m 36.23s [1] | ||||
Declination | (δ) | +20° 35′ 57.2″ [1] | ||||
Mass | (m) | 0.961 +0.032 −0.029[1] M☉ | ||||
Radius | (r) | 0.928 +0.055 −0.040[1] R☉ | ||||
Temperature | (T) | 5766±99[1] K | ||||
Metallicity | [Fe/H] | -0.15±0.05[1] | ||||
Age | 3.34 +1.95 −1.49 [1] Gyr | |||||
Physical characteristics | ||||||
Mass | (m) | 16.3 +6.0 −6.1[1] M⊕ | ||||
Radius | (r) | +0.14 −0.11 2.23[1] R⊕ | ||||
Density | (ρ) | +3.400 −3.100 7.890[1] g cm−3 | ||||
Temperature | (T) | 546 K (273 °C; 523 °F) +19 −18 K | ||||
Orbital elements | ||||||
Semi-major axis | (a) | 0.241 +0.019 −0.017[1] AU | ||||
Eccentricity | (e) | 0[1] | ||||
Orbital period | (P) | 41.6855 +0.0030 −0.0031[1] d | ||||
Inclination | (i) | +0.17 −0.14 89.55[1]° | ||||
Discovery information | ||||||
Discovery date | 2016 | |||||
Discoverer(s) | ||||||
Discovery method | Transit | |||||
Discovery site | Kepler Space Observatory, La Silla, Chile | |||||
Discovery status | Confirmed |
BD+20594b (Also known as K2-56b[1]) is an exoplanet discovered by the Kepler spacecraft in collaboration with the HARPS spectrometer at La Silla in Chile.
Naming
BD+20594b indicates that the planet circles a star found in the Bonner Durchmusterung catalogue, BD +20° 594, the 594th entry in the +20-degree zone (declinations from +19 to +20 degrees); and it is the first planet discovered orbiting that star.
K2-56b indicates that the planet circles a star catalogued in the Kepler 2 mission catalogue, part of the extended K2 Kepler mission, the 56th one in the catalogue; and that it is the first planet discovered orbiting that star.
Planet
BD+20594b is substantially smaller than Neptune with a radius of 2.2 R⊕ and a mass of 16.31 M⊕.[2] Taking the estimates on its radius and mass at face value, the composition of the planet would be rocky, hence making it classified as a Mega-Earth. BD+20594b's exact composition is still unknown.
The planet was first discovered on January 28, 2016 by astrophysicist Néstor Espinoza and his team from the Catholic University of Chile, using data from the two-wheeled Kepler mission (K2). It orbits a K-type star 496.08 light years away in the constellation Taurus.[3]
It is believed that most planets with a radius greater than 1.6 times the Earth are not usually rocky,[4] making BD+20594b an exception to this rule along with Kepler-10c and K2-3d.