75 Ceti

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75 Ceti
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension 02h 32m 09.422s[1]
Declination −01° 02′ 05.62″[1]
Apparent magnitude (V) +5.36
Spectral type G3 III
Proper motion (μ) RA: -24.72 ± 0.46[1] mas/yr
Dec.: -32.08 ± 0.40[1] mas/yr
Parallax (π) 12.28 ± 0.45[1] mas
Distance 266 ± 10 ly
(81 ± 3 pc)
Absolute magnitude (MV) 0.808[2]
Mass 2.16[2] M
Radius 10.5 (9.5–11.5) R
Luminosity 53.7 L
Surface gravity (log g) 2.75[2] cgs
Temperature 4,784[2] K
Metallicity −0.05[2]
Other designations
HD 15779, HIP 11791, HR 739, SAO 129959, BD–01° 353
Database references
Exoplanet Archive data
Extrasolar Planets

75 Ceti is a G-type giant with at least one planet.[3]

In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, 75 Ceti itself is known as the Tenth Star of Circular Celestial Granary.[4]

The planet's discoverers consider this planet b "typical" of gas giants.[3] Note that (like many recorded planets) b takes in much more insolation than does Jupiter and, indeed, Earth.[5]

The 75 Ceti planetary system[3]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b >3 MJ 2.1 691.9 ± 3.6 0.117 ± 0.048

There may be additional periodic factors in the data, corresponding to m sin i of around 0.4 MJ and 1 MJ, at distances of ∼0.9 AU and ∼4 AU. If these are confirmed, they are more irradiated than Earth as well.


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. Bibcode:2007A&A...474..653V. arXiv:0708.1752Freely accessible. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. ^ a b c d e Liu, Y. J.; et al. (2007), "The abundances of nearby red clump giants", Monthly Notices of the Royal Astronomical Society, 382 (2): 553–66, Bibcode:2007MNRAS.382..553L, doi:10.1111/j.1365-2966.2007.11852.x. 
  3. ^ a b c Sato, Bun'ei; et al. (2012). "Substellar Companions to Seven Evolved Intermediate-Mass Stars". Publications of the Astronomical Society of Japan. 64 (6). 135. Bibcode:2012PASJ...64..135S. arXiv:1207.3141Freely accessible. doi:10.1093/pasj/64.6.135. 
  4. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日
  5. ^ Square root of luminosity means that an Earth like planet would have to be >7 AU from the star.