Gliese 180

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Gliese 180
Diagram showing star positions and boundaries of the constellation of Eridanus and its surroundings
Cercle rouge 100%.svg
A star chart of the constellation of Eridanus showing the position of Gliese 180
Observation data
Epoch J2000      Equinox J2000
Constellation Eridanus
Right ascension 04h 53m 49.9798s[1]
Declination −17° 46′ 24.294″[1]
Apparent magnitude (V) 10.894[2]
Characteristics
Evolutionary stage Red dwarf
Spectral type M2[2]
U−B color index 1.155[2]
B−V color index 1.549[2]
V−R color index 1.018[2]
R−I color index 1.205[2]
J−H color index 0.553[2]
J−K color index 0.815[2]
Astrometry
Radial velocity (Rv) 14.55 ± 0.24[3] km/s
Proper motion (μ) RA: 405.2 ± 3.1[4] mas/yr
Dec.: -650.6 ± 3.2[4] mas/yr
Parallax (π) 80.89 ± 1.97[5] mas
Distance 40.3 ± 1.0 ly
(12.4 ± 0.3 pc)
Absolute magnitude (MV) 10.48[2]
Details[6]
Mass 0.39 M
Radius 0.42 R
Temperature 3562 K
Other designations
LHS 1712, CSI-17-04516, HIC 22762, HIP 22762, LFT 377, L 736-30, LP 776-27, LPM  198, LTT 2116, 2MASS J04534995-1746235, NLTT 14144, PLX 1097, PLX 1097.00, TYC 5903-680-1, [RHG95] 838
Database references
SIMBAD data
Exoplanet Archive data
ARICNS data

Gliese  180 (often shortened to GJ 180), is a red dwarf star, known to have two planets Gliese 180 b and Gliese 180 c.[3] It is located approximately 40 light-years away from Earth.[5]

According to the Planetary Habitability Laboratory (PHL) in Puerto Rico, both worlds in the system may be classifiable as potentially habitable planets. Planet Gliese 180 b and Gliese 180 c have masses of 6.4 and 8.3 Earth masses, respectively.[7] However, Dr Mikko Tuomi, of the UK’s University of Hertfordshire, whose team identified the planets, disagreed, stating:

"The PHL adds some sort of an “extended HZ”, which I, frankly, do not know how it’s calculated, but that adds some areas of potential habitability to the inner and outer edges of the HZ as we have defined it. They included the inner companion of the GJ 180 system (planet b) that we consider too hot to be potentially habitable.”[7]
The Gliese 180 planetary system[8][9]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 0.02611 ± 0.00558 MJ 0.103 ± 0.0008 17.38 ± 0.016 0.11 ± 0.03
с 0.02014 ± 0.00126 MJ 0.129 ± 0.01 24.329 ± 0.014 0.09 ± 0.07

External Resources[edit]

References[edit]

  1. ^ a b van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357 
  2. ^ a b c d e f g h i Koen, C.; Kilkenny, D.; van Wyk, F.; Marang, F. (April 21, 2010), "UBV(RI)CJHK observations of Hipparcos-selected nearby stars", Monthly Notices of the Royal Astronomical Society, 403 (4): 1949–1968, Bibcode:2010MNRAS.403.1949K, doi:10.1111/j.1365-2966.2009.16182.x 
  3. ^ a b Wenger; et al. (March 2016), "GJ 180", The SIMBAD astronomical database, Strasbourg, France: Centre de Données astronomiques de Strasbourg, 143, pp. 9–22, arXiv:astro-ph/0002110Freely accessible, Bibcode:2000A&AS..143....9W, doi:10.1051/aas:2000332 
  4. ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355 (2): L27–L30, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862 
  5. ^ a b European Space Agency (1997), The Hipparcos and Tycho catalogues; astronomic and photometric star catalogues derived from the ESA Hipparcos Space Astronomy Mission, ESA SP, 1200, Noordwijk, Netherlands: ESA Publications Division, Bibcode:1997ESASP1200.....E, ISBN 9290923997, OCLC 222398081 
  6. ^ Turnbull, Margaret C. (October 2015), ExoCat-1: The Nearby Stellar Systems Catalog for Exoplanet Imaging Missions, arXiv:1510.01731Freely accessible, Bibcode:2015arXiv151001731T 
  7. ^ a b Sutherland, Paul (March 5, 2014). "Habitable planets common around red dwarf stars". Sen. Sen Corporation Ltd. 
  8. ^ "Planet Gj 180 b". Extrasolar Planets Encyclopaedia. Retrieved 2014-05-25. 
  9. ^ "Planet Gj 180 c". Extrasolar Planets Encyclopaedia. Retrieved 2014-05-25.