Astronomy:Gliese 1214

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Short description: Star in the constellation Ophiuchus
Gliese 1214
Morgan-Keenan spectral classification zoom.png

Gliese 1214 is a M-class dwarf star
Observation data
Equinox J2000.0]] (ICRS)
Constellation Ophiuchus[1]
Right ascension  17h 15m 18.9337s[2]
Declination +04° 57′ 50.0646″[2]
Apparent magnitude (V) 14.71±0.03[3]
Characteristics
Spectral type M4.5[4]
Apparent magnitude (B) 16.40[5]
Apparent magnitude (R) 14.394 ± 0.17[5]
Apparent magnitude (I) 11.52 ± 0.03[3]
Apparent magnitude (J) 9.750±0.024[6]
Apparent magnitude (H) 9.094±0.024[6]
Apparent magnitude (K) 8.782±0.020[6]
B−V color index 1.73[7]
V−R color index 0.9
R−I color index 2.7
Variable type planetary transit[8]
Astrometry
Radial velocity (Rv)+21.1±1.0[3] km/s
Proper motion (μ) RA: 580.447±0.479[2]mas/yr
Dec.: −749.588±0.221[2] mas/yr
Parallax (π)68.2653 ± 0.1723[2] mas
Distance47.8 ± 0.1 ly
(14.65 ± 0.04 pc)
Absolute magnitude (MV)14.10
Details
Mass0.181±0.005[9] M
Radius0.204±0.0085[9] R
Luminosity0.00351±0.00010[9] L
Surface gravity (log g)4.991±0.029[8] cgs
Temperature3,111+69
−66
[9] K
Metallicity [Fe/H]0.11±0.09[9] dex
Rotation125±5 d[10]
Age5–10[11] Gyr
Other designations
LHS 3275, G 139-21, NLTT 44431, 2MASS J17151894+0457496, LSPM J1715+0457, UBV M 53793, USNO-B1.0 0949-00280047, GEN# +9.80139021.[5]
Database references
SIMBADdata
Exoplanet Archivedata
ARICNSdata
Extrasolar Planets
Encyclopaedia
data

Gliese 1214 is a dim M4.5[4] red dwarf in the constellation Ophiuchus with an apparent magnitude of 14.7.[3] It is located at a distance of approximately 47 light years from Earth.[12] The star is about one-fifth the radius of the Sun[13] with a surface temperature estimated to be 3,110 K (2,840 °C; 5,140 °F).[9] Its luminosity is only 0.35% that of the Sun.[9]

The estimate for the stellar radius is 15% larger than predicted by theoretical models.[8] It also shows a 1% intrinsic variability in the near-infrared probably caused by stellar spots.[3] The star is rotating slowly, with a period that is most likely an integer multiple of 53 days. It is probably at least three billion years old and a member of the old thin disk of the Milky Way.[3] Although GJ 1214 has a low to moderate level of magnetic activity, it does undergo flares and is a source of X-ray emission with a base luminosity of 7.4×1025 erg s−1. The temperature of the stellar corona is estimated to be about 3.5×106 K.[11]

In 2021-2022, the star is suspected to be in the low-activity phase of its magnetic starspot cycle.[14]

Planetary system

In mid-December 2009, a team of Harvard-Smithsonian astronomers announced the discovery of a companion extrasolar planet, Gliese 1214 b, potentially composed largely of water and having the mass and diameter of a super-Earth.[8][13]

The Gliese 1214 planetary system[3][8]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 8.17±0.43[15] M 0.0143 ± 0.0019 1.58040456 ± 1.6x10−7[16] <0.27 88.17° 2.742+0.050−0.053[15] R
The newly discovered super-Earth surrounding the nearby star GJ 1214.
This artist's impression shows how the newly discovered super-Earth orbiting the nearby star GJ 1214 may look. Credit: ESO/L. Calçada

Discovered by the MEarth project and investigated further by the HARPS spectrograph on ESO’s 3.6-metre telescope at La Silla, GJ 1214 b is the second super-Earth exoplanet for which astronomers have determined the mass and radius, giving vital clues about its structure. It is also the first super-Earth around which an atmosphere has been found. A search for additional planets using transit timing variations was negative.[3]

No transit-time variations have yet been found for this transit. As of 2012, "the given data does not allow us to conclude that there is a [second] planet in the mass range 0.1–5 Earth-masses and the period range 0.76–1.23 or 1.91–3.18 days."[16] The X-ray flux from the host star is estimated to have stripped 2–5.6 M from the planet over the lifetime of the system.[11]

In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project.[17]

See also

References

  1. Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific 99 (617): 695–699. doi:10.1086/132034. Bibcode1987PASP...99..695R.  Vizier query form
  2. Jump up to: 2.0 2.1 2.2 2.3 2.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  3. Jump up to: 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Berta, Zachory K. et al. (2011). "The GJ1214 Super-Earth System: Stellar Variability, New Transits, and a Search for Additional Planets". The Astrophysical Journal 736 (1): 12. doi:10.1088/0004-637X/736/1/12. Bibcode2011ApJ...736...12B. 
  4. Jump up to: 4.0 4.1 Rojas-Ayala, Bárbara et al. (2010). "Metal-rich M-Dwarf Planet Hosts: Metallicities with K-band Spectra". The Astrophysical Journal Letters 720 (1): L113–L118. doi:10.1088/2041-8205/720/1/L113. Bibcode2010ApJ...720L.113R. 
  5. Jump up to: 5.0 5.1 5.2 "Gliese 1214". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Gliese+1214. 
  6. Jump up to: 6.0 6.1 6.2 Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W. et al. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal 131 (2): 1163–1183. doi:10.1086/498708. ISSN 0004-6256. Bibcode2006AJ....131.1163S. https://ui.adsabs.harvard.edu/abs/2006AJ....131.1163S/abstract.  Vizier catalog entry
  7. van Altena, William F. et al.. The General Catalogue of Trigonometric Stellar Parallaxes. Yale University Observatory. Vizier catalog entry
  8. Jump up to: 8.0 8.1 8.2 8.3 8.4 Charbonneau, David et al. (2009). "A super-Earth transiting a nearby low-mass star". Nature 462 (7275): 891–894. doi:10.1038/nature08679. PMID 20016595. Bibcode2009Natur.462..891C. 
  9. Jump up to: 9.0 9.1 9.2 9.3 9.4 9.5 9.6 Pineda, J. Sebastian; Youngblood, Allison; France, Kevin (September 2021). "The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars". The Astrophysical Journal 918 (1): 23. doi:10.3847/1538-4357/ac0aea. 40. Bibcode2021ApJ...918...40P. 
  10. Mallonn, M. et al. (2018). "GJ 1214: Rotation period, starspots, and uncertainty on the optical slope of the transmission spectrum". Astronomy and Astrophysics 614: A35. doi:10.1051/0004-6361/201732300. Bibcode2018A&A...614A..35M. 
  11. Jump up to: 11.0 11.1 11.2 Lalitha, S. et al. (July 2014). "X-Ray Emission from the Super-Earth Host GJ 1214". The Astrophysical Journal Letters 790 (1): 5. doi:10.1088/2041-8205/790/1/L11. L11. Bibcode2014ApJ...790L..11L. 
  12. Anglada-Escudé, Guillem; Rojas-Ayala, Bárbara; Boss, Alan P.; Weinberger, Alycia J.; Lloyd, James P. (2012). "GJ 1214b revised. Improved trigonometric parallax, stellar parameters, orbital solution, and bulk properties for the super-Earth GJ 1214b". Astronomy & Astrophysics 551: A48. doi:10.1051/0004-6361/201219250. Bibcode2013A&A...551A..48A. 
  13. Jump up to: 13.0 13.1 David A. Aguilar (2009-12-16). "Astronomers Find Super-Earth Using Amateur, Off-the-Shelf Technology". Harvard-Smithsonian Center for Astrophysics. http://www.cfa.harvard.edu/news/2009/pr200924.html. Retrieved December 16, 2009. 
  14. Henry, Gregory W.; Bean, Jacob L. (2023), C14 Automatic Imaging Telescope Photometry of GJ 1214 
  15. Jump up to: 15.0 15.1 Cloutier, Ryan; Charbonneau, David; Deming, Drake; Bonfils, Xavier; Astudillo-Defru, Nicola (2021), "A More Precise Mass for GJ 1214 b and the Frequency of Multiplanet Systems Around Mid-M Dwarfs", The Astronomical Journal 162 (5): 174, doi:10.3847/1538-3881/ac1584 
  16. Jump up to: 16.0 16.1 Kennet B. W. Harpsøe (2012). "The Transiting System Gliese 1214". Astronomy & Astrophysics 549: A10. doi:10.1051/0004-6361/201219996. Bibcode2013A&A...549A..10H. 
  17. "List of ExoWorlds 2022". IAU. 8 August 2022. https://www.nameexoworlds.iau.org/2022exoworlds. 

External links

Coordinates: Sky map 17h 15m 18.94s, +4° 57′ 49.7″