Gliese 581d

Gliese 581d
Size comparison of Gliese 581d with Earth and Neptune.
(Based on selected hypothetical modeled compositions)
Discovery[1]
Discovered byUdry et al.
Discovery siteLa Silla Observatory, Chile
Discovery date24 April 2007
Radial velocity
Orbital characteristics[2]
0.21847 ± 0.00028 AU (32,683,000 ± 42,000 km)[3]
Eccentricity0.205±0.08
66.64±0.08 d
245141.6407±4.19 JD
2°±23°
Semi-amplitude2.20±0.19 m/s
StarGliese 581
Physical characteristics
Mass≥5.6±0.6 M🜨[3]

Gliese 581d /ˈɡliːzə/ (often shortened to Gl 581d or GJ 581d) is a doubtful, and frequently disputed, exoplanet candidate orbiting within the Gliese 581 system, approximately 20.4 light-years away in the Libra constellation. It was the third planet claimed in the system and the fourth (in a 4-planet model) or fifth (in a disproven 5- or 6-planet model) in order from the star. Multiple subsequent studies found that the planetary signal in fact originates from stellar activity, and thus the planet does not exist,[4][5][6][7][8] but this remains disputed.[9]

Though significantly more massive than Earth (at a minimum mass of 6.98 Earth masses), this super-Earth was the first exoplanet of relatively low mass regarded as orbiting within the habitable zone of its parent star. Assuming its existence, computer climate simulations have confirmed the possibility of the existence of surface water and these factors combine to a relatively high measure of planetary habitability.[10][11]

  1. ^ Cite error: The named reference Udry was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Hatzes2013 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Vogt was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference SCI-20140703 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Hatzes2016 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Trifonov2018 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Dodson-Robinson2022 was invoked but never defined (see the help page).
  8. ^ von Stauffenberg, A.; Trifonov, T.; Quirrenbach, A.; Reffert, S.; Kaminski, A.; Dreizler, S.; Ribas, I.; Reiners, A.; Kürster, M.; Twicken, J. D.; Rapetti, D.; Caballero, J. A.; Amado, P. J.; Béjar, V. J. S.; Cifuentes, C. (August 2024). "The CARMENES search for exoplanets around M dwarfs: Revisiting the GJ 581 multi-planetary system with new Doppler measurements from CARMENES, HARPS, and HIRES". Astronomy & Astrophysics. 688: A112. arXiv:2407.11520. Bibcode:2024A&A...688A.112V. doi:10.1051/0004-6361/202449375. ISSN 0004-6361.
  9. ^ Cite error: The named reference Cuntz2024 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Bloh was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Selsis2007 was invoked but never defined (see the help page).