Gliese 581 f

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Gliese 581 f
Extrasolar planet List of extrasolar planets
Gliese 581 system compared to solar system.jpg
The orbits of planets in the Gliese 581 system compared to those of our own solar system
Parent star
Star Gliese 581
Constellation Libra
Right ascension (α) 15h 19m 26s
Declination (δ) −07° 43′ 20″
Apparent magnitude (mV) 10.55
Distance 20.3 ± 0.3 ly
(6.2 ± 0.1 pc)
Spectral type M3V
Mass (m) 0.31 M
Radius (r) 0.29 R
Temperature (T) 3480 ± 48 K
Metallicity [Fe/H] -0.33 ± 0.12
Age 7 – 11 Gyr
Orbital elements
Epoch JD 2451409.762[1]
Semimajor axis (a) 0.758 ± 0.015[1] AU
Eccentricity (e) 0[1]
Orbital period (P) 433 ± 13[1] d
(1.19 y)
    (10400 h)
Mean anomaly (M) 118 ± 68[1]°
Semi-amplitude (K) 1.30 ± 0.22[1] m/s
Physical characteristics
Minimum mass (m sin i) 7.0 ± 1.2[1] M
Discovery information
Discovery date 29 September 2010
Discoverer(s) Vogt et al.
Discovery method Radial velocity
Discovery site Keck Observatory, Hawaii
Discovery status Unconfirmed[2]
Database references
Extrasolar Planets

Gliese 581 f or Gl 581 f is an unconfirmed exoplanet in the Gliese 581 system, located 20 light years (about 120 trillion miles) from Earth. It is the fifth planet discovered in the system and the sixth known in order from the star. Its discovery was announced September 29, 2010.


The planet was detected using radial velocity measurements combining the data from the HIRES instrument of the Keck 1 telescope and the HARPS instrument of ESO's 3.6m telescope at La Silla Observatory.[1]

The planet has a minimum mass of 7.0 Earth masses, suggesting that it may be either a large terrestrial planet (super earth) or a gaseous planet similar to Neptune. It orbits at a distance from its star of 0.758 AU, slightly more than Venus's distance from our Sun, but it is likely to be far too cold at its surface for liquid water.


The existence of Gliese 581 f is controversial. Follow-up studies incorporating updated data from HARPS have not confirmed its existence,[3][4][5] and it appears the radial velocity variations at this period may instead be associated with the stellar activity cycle of Gliese 581 itself rather than any orbiting planet.[6]


  1. ^ a b c d e f g h Vogt, Steven S.; Butler, R. Paul; Rivera, Eugenio J.; Haghighipour, Nader; Henry, Gregory W.; Williamson, Michael H. (2010-09-29). "The Lick-Carnegie Exoplanet Survey: A 3.1 M_Earth Planet in the Habitable Zone of the Nearby M3V Star Gliese 581". arXiv:1009.5733.
  2. ^ "Notes for star Gl 581". The Extrasolar Planets Encyclopaedia. Retrieved 2010-10-11. 
  3. ^ T. Forveille, X. Bonfils, X.Delfosse, R. Alonso, S. Udry, F. Bouchy, M. Gillon, C. Lovis, V. Neves, M. Mayor, F. Pepe, D. Queloz, N.C. Santos, D. Segransan, J.M. Almenara, H. Deeg, M. Rabus (2011). "The HARPS search for southern extra-solar planets XXXII. Only 4 planets in the Gl 581 system". arXiv:1109.2505 [astro-ph.EP].
  4. ^ Baluev, Roman V. (2013). "The impact of red noise in radial velocity planet searches: only three planets orbiting GJ 581?". Monthly Notices of the Royal Astronomical Society 429 (3): 2052–2068. arXiv:1209.3154. Bibcode:2013MNRAS.429.2052B. doi:10.1093/mnras/sts476. 
  5. ^ Tuomi, Mikko; Jenkins, James S. (2012). "Counting the number of planets around GJ 581. False positive rate of Bayesian signal detection methods". arXiv:1211.1280 [astro-ph.EP].
  6. ^ Robertson, Paul; Endl, Michael; Cochran, William D.; Dodson-Robinson, Sarah E. (2013). "Hα Activity of Old M Dwarfs: Stellar Cycles and Mean Activity Levels for 93 Low-mass Stars in the Solar Neighborhood". The Astrophysical Journal 764 (1): article id. 3. arXiv:1211.6091. Bibcode:2013ApJ...764....3R. doi:10.1088/0004-637X/764/1/3. 

External links[edit]

Coordinates: Sky map 15h 19m 27s, −07° 43′ 19″