KELT-20, also known as MASCARA-2, is an A2 main sequence star in the constellation of Cygnus, about 447 light years away.

KELT-20
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cygnus
Right ascension 19h 38m 38.735s[1]
Declination +31° 31′ 09.22″[1]
Apparent magnitude (V) 7.58[2]
Characteristics
Evolutionary stage main sequence star
Spectral type A2V[3]
Variable type planetary transit
Astrometry
Proper motion (μ) RA: 3.096±0.068 mas/yr[1]
Dec.: −6.157±0.075 mas/yr[1]
Parallax (π)7.3015 ± 0.0433 mas[1]
Distance447 ± 3 ly
(137.0 ± 0.8 pc)
Details
Mass2.3[4] M
Radius1.6[4] R
Luminosity15.7[4] L
Surface gravity (log g)4.38[4] cgs
Temperature9,032[4] K
Metallicity [Fe/H]−0.02±0.07[5] dex
Age0.200[5] Gyr
Other designations
HD 185603, HIP 96618, MASCARA-2, KELT-20
Database references
SIMBADdata

Nomenclature

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KELT-20 is the star's KELT designation. It is also designated as MASCARA-2 meaning that it is the second star observed by the MASCARA exoplanet search program. Its Henry Draper Catalogue designation is HD 185603, and its Hipparcos designation is HIP 96618.

Planetary system

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In 2017, the discovery of the planet KELT-20b was announced.[6][7][8]

The KELT-20 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 3.382 MJ 0.05 3.6127647 86.12° 1.741 RJ

References

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  1. ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862. ISBN 978-0333750889.
  3. ^ Lund, Michael B.; et al. (2017). "KELT-20b: A Giant Planet with a Period of P ∼ 3.5 days Transiting the V ∼ 7.6 Early a Star HD 185603". The Astronomical Journal. 154 (5): 194. arXiv:1707.01518. Bibcode:2017AJ....154..194L. doi:10.3847/1538-3881/aa8f95.
  4. ^ a b c d e Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881.
  5. ^ a b Talens, G. J. J.; Justesen, A. B.; Albrecht, S.; McCormac, J.; Van Eylen, V.; Otten, G. P. P. L.; Murgas, F.; Palle, E.; Pollacco, D.; Stuik, R.; Spronck, J. F. P.; Lesage, A. -L.; Grundahl, F.; Fredslund Andersen, M.; Antoci, V.; Snellen, I. A. G. (2018). "MASCARA-2 b. A hot Jupiter transiting the mV = 7.6 A-star HD 185603". Astronomy and Astrophysics. 612. arXiv:1707.01500. Bibcode:2018A&A...612A..57T. doi:10.1051/0004-6361/201731512. S2CID 119422884.
  6. ^ Yan, F.; Reiners, A.; Pallé, E.; Shulyak, D.; Stangret, M.; Molaverdikhani, K.; Nortmann, L.; Mollière, P.; Henning, Th.; Casasayas-Barris, N.; Cont, D.; Chen, G.; Czesla, S.; Sánchez-López, A.; López-Puertas, M.; Ribas, I.; Quirrenbach, A.; Caballero, J. A.; Amado, P. J.; Galadí-Enríquez, D.; Khalafinejad, S.; Lara, L. M.; Montes, D.; Morello, G.; Nagel, E.; Sedaghati, E.; Zapatero Osorio, M. R.; Zechmeister, M. (2022), "Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b", Astronomy & Astrophysics, 659: A7, arXiv:2201.08759, Bibcode:2022A&A...659A...7Y, doi:10.1051/0004-6361/202142395, S2CID 246210387
  7. ^ Fu, Guangwei; Sing, David K.; Lothringer, Joshua D.; Deming, Drake; Ih, Jegug; Kempton, Eliza M. -R.; Malik, Matej; Komacek, Thaddeus D.; Mansfield, Megan; Bean, Jacob L. (2022), "Strong H2O and CO Emission Features in the Spectrum of KELT-20b Driven by Stellar UV Irradiation", The Astrophysical Journal Letters, 925 (1): L3, arXiv:2201.02261, Bibcode:2022ApJ...925L...3F, doi:10.3847/2041-8213/ac4968
  8. ^ Kasper, David; Bean, Jacob L.; Line, Michael R.; Seifahrt, Andreas; Brady, Madison T.; Lothringer, Joshua; Pino, Lorenzo; Fu, Guangwei; Pelletier, Stefan; Stürmer, Julian; Benneke, Björn; Brogi, Matteo; Désert, Jean-Michel (2023), "Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b", The Astronomical Journal, 165 (1): 7, arXiv:2208.04759, Bibcode:2023AJ....165....7K, doi:10.3847/1538-3881/ac9f40