Astronomy:KELT-20

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Short description: Star in Cygnus
KELT-20
Observation data
Equinox J2000.0]] (ICRS)
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[1] mas/yr
Dec.: −6.157±0.075[1] mas/yr
Parallax (π)7.3015 ± 0.0433[1] mas
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

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

Nomenclature

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

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

  1. 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  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. et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27. doi:10.1888/0333750888/2862. ISBN 978-0333750889. Bibcode2000A&A...355L..27H. 
  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. doi:10.3847/1538-3881/aa8f95. Bibcode2017AJ....154..194L. 
  4. 4.0 4.1 4.2 4.3 4.4 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode2019AJ....158..138S. 
  5. 5.0 5.1 Talens, G. J. J.; Justesen, A. B.; Albrecht, S.; McCormac, J.; Van Eylen, V.; Otten, G. P. P. L.; Murgas, F.; Palle, E. et al. (2018). "MASCARA-2 b. A hot Jupiter transiting the mV = 7.6 A-star HD 185603". Astronomy and Astrophysics 612. doi:10.1051/0004-6361/201731512. Bibcode2018A&A...612A..57T. 
  6. Yan, F.; Reiners, A.; Pallé, E.; Shulyak, D.; Stangret, M.; Molaverdikhani, K.; Nortmann, L.; Mollière, P. et al. (2022), "Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b", Astronomy & Astrophysics 659: A7, doi:10.1051/0004-6361/202142395, Bibcode2022A&A...659A...7Y 
  7. Fu, Guangwei; Sing, David K.; Lothringer, Joshua D.; Deming, Drake; Ih, Jegug; Kempton, Eliza M. -R.; Malik, Matej; Komacek, Thaddeus D. et al. (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, doi:10.3847/2041-8213/ac4968, Bibcode2022ApJ...925L...3F 
  8. Kasper, David; Bean, Jacob L.; Line, Michael R.; Seifahrt, Andreas; Brady, Madison T.; Lothringer, Joshua; Pino, Lorenzo; Fu, Guangwei et al. (2023), "Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b", The Astronomical Journal 165 (1): 7, doi:10.3847/1538-3881/ac9f40, Bibcode2023AJ....165....7K