BD+20 594b

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BD +20° 594 b
Exoplanet List of exoplanets
Size comparison
Neptune BD+20 594b
Neptune Exoplanet
Parent star
Star BD+20°594
Constellation Aries
Right ascension (α) 03h 34m 36.2296s[1]
Declination (δ) +20° 35′ 57.268″[1]
Distance560±20[1] ly
(173±7[1] pc)
Mass (m) 0.961 +0.032
−0.029
[2] M
Radius (r) 0.928 +0.055
−0.040
[2] R
Temperature (T) 5766±99[2] K
Metallicity [Fe/H] -0.15±0.05[2]
Age 3.34 +1.95
−1.49
[2] Gyr
Physical characteristics
Mass(m)16.3 +6.0
−6.1
[2] M
Radius(r)2.23+0.14
−0.11
[2] R
Density(ρ)7.890+3.400
−3.100
[2] 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
[2] AU
Eccentricity (e) 0[2]
Orbital period(P) 41.6855 +0.0030
−0.0031
[2] d
Inclination (i) 89.55+0.17
−0.14
[2]°
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[2]) is an exoplanet discovered by the Kepler spacecraft in collaboration with the HARPS spectrometer at La Silla in Chile.

Naming[edit]

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 that 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[edit]

With a radius of 2.2 R and a mass of 16.31 M, BD+20594b is substantially smaller than Neptune.[3] Taking the estimates of 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 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.[4]

It is believed that planets with a radius greater than 1.6 times the Earth's are not usually rocky,[5] making BD+20594b an exception to this rule along with Kepler-10c and K2-3d.

See also[edit]

References[edit]

  1. ^ a b c d Brown, A. G. A; et al. (2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy and Astrophysics. 595. A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512.Gaia Data Release 1 catalog entry
  2. ^ a b c d e f g h i j k l m "CONFIRMED PLANET OVERVIEW PAGE". NASA Exoplanet Archive. NASA. Retrieved 2016-08-11.
  3. ^ http://exoplanet.eu/catalog/bd%2B20_594_b/
  4. ^ Espinoza, Néstor; Brahm, Rafael; Jordán, Andrés; Jenkins, James S; Rojas, Felipe; Jofré, Paula; Mädler, Thomas; Rabus, Markus; Chanamé, Julio; Pantoja, Blake; Soto, Maritza G; Morzinski, Katie M; Males, Jared R; Ward-Duong, Kimberly; Close, Laird M (2016). "Discovery and Validation of a High-Density sub-Neptune from the K2 Mission". The Astrophysical Journal. 830 (1): 43. arXiv:1601.07608. Bibcode:2016ApJ...830...43E. doi:10.3847/0004-637X/830/1/43.
  5. ^ Rogers, Leslie A; Brahm, Rafael; Jordán, Andrés; Jenkins, James S; Rojas, Felipe; Jofré, Paula; Mädler, Thomas; Rabus, Markus; Chanamé, Julio; Pantoja, Blake; Soto, Maritza G; Morzinski, Katie M; Males, Jared R; Ward-Duong, Kimberly; Close, Laird M (2015). "Most 1.6 Earth-radius Planets are Not Rocky". The Astrophysical Journal. 801 (1): 41. arXiv:1407.4457. Bibcode:2015ApJ...801...41R. doi:10.1088/0004-637X/801/1/41.

External links[edit]

Coordinates: Sky map 03h 34m 36.23s, +20° 35′ 57.2″