94 Ceti

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94 Ceti A / B
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension  03h 12m 46.43719s[1]
Declination −01° 11′ 45.9613″[1]
Apparent magnitude (V) +5.070[2]
Spectral type F8V / M3V / M
U−B color index +0.09[3]
B−V color index +0.56[3]
Radial velocity (Rv)+18.96 ± 0.08[4] km/s
Proper motion (μ) RA: 194.56[1] mas/yr
Dec.: −69.01[1] mas/yr
Parallax (π)44.29 ± 0.28[1] mas
Distance73.6 ± 0.5 ly
(22.6 ± 0.1 pc)
Absolute magnitude (MV)3.32
Primary94 Ceti A
Companion94 Ceti BC
Period (P)2029±41 yr
Semi-major axis (a)220±5 AU
Eccentricity (e)0.26±0.01
Inclination (i)104±2°
Longitude of the node (Ω)97±2°
Argument of periastron (ω)
Primary94 Ceti B
Companion94 Ceti C
Period (P)378.35+0.36
Semi-major axis (a)0.984±0.007 AU
Eccentricity (e)0.360±0.005
Inclination (i)108.323+0.581
Longitude of the node (Ω)191.496+1.602
Periastron epoch (T)MJD 55113.904±0.220
Argument of periastron (ω)
Mass1.30[7] M
Radius1.898 ± 0.070[8] R
Luminosity4.02 ± 0.05[9] L
Surface gravity (log g)3.98 ± 0.10[7] cgs
Temperature6,055 ± 10.0[10] K
Metallicity [Fe/H]1.15 ± 0.07[7] dex
Rotational velocity (v sin i)8.4 ± 0.8[7] km/s
Age4.8[9] Gyr
Other designations
BD-01° 457, FK5 116, GJ 128, HD 19994, HIP 14954, HR 962, LTT 1515, SAO 130355.
Database references
Extrasolar Planets

94 Ceti (HD 19994) is a trinary star system approximately 73 light-years away in the constellation Cetus.

94 Ceti A is a yellow-white dwarf star with about 1.3 times the mass of the Sun while 94 Ceti B and C are red dwarf stars.

An infrared excess has been detected around the primary, most likely indicating the presence of a circumstellar disk at a radius of 95 AU. The temperature of this dust is 40 K.[11]

Stellar system[edit]

This system is a hierarchical triple star system with 94 Ceti A being orbited by 94 Ceti BC, a pair of M dwarfs, in 2000 years. 94 Ceti B and C meanwhile orbit each other in a 1-year orbit.[5]

Planetary system[edit]

On 7 August 2000, a planet was announced by the Geneva Extrasolar Planet Search team as a result of radial velocity measurements taken with the Swiss 1.2-metre Leonhard Euler Telescope at La Silla Observatory in Chile.[12] It is most stable if its inclination is either 65 or 115, ± 3.[13]

The 94 Ceti planetary system[13]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b 1.855 ± 0.045 MJ 1.427 535.7 ± 3.1 0.30 ± 0.04

See also[edit]


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. ^ Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
  3. ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's Ubv Data. Bibcode:1986EgUBV........0M.
  4. ^ Nidever, David L.; et al. (2013). "Radial Velocities for 889 Late-Type Stars". The Astrophysical Journal Supplement Series. 141 (2): 503–522. arXiv:astro-ph/0112477. Bibcode:2002ApJS..141..503N. doi:10.1086/340570.
  5. ^ a b Wiegert, J.; et al. (2016). "94 Ceti: A triple star with a planet and dust disc". Monthly Notices of the Royal Astronomical Society. 462 (2): 1735–1748. arXiv:1607.03038. Bibcode:2016MNRAS.462.1735W. doi:10.1093/mnras/stw1682.
  6. ^ Röll, Tristan Alexander (2011). Astrometric search for extrasolar planets in stellar multiple systems (PDF) (PhD). Friedrich-Schiller-University Jena.
  7. ^ a b c d Fuhrmann, K. (2008). "Nearby stars of the Galactic disc and halo - IV". Monthly Notices of the Royal Astronomical Society. 384 (1): 173–224. Bibcode:2008MNRAS.384..173F. doi:10.1111/j.1365-2966.2007.12671.x.
  8. ^ van Belle, G. T.; von Brau, K. (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal. 694 (2): 1085–1098. arXiv:0901.1206. Bibcode:2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085.
  9. ^ a b Boyajian, Tabetha S.; et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal, 771 (1): 31, arXiv:1306.2974, Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40, 40. See Table 3.
  10. ^ Kovtyukh, V. V.; Soubiran, C.; Belik, S. I.; Gorlova, N. I. (2003). "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios". Astronomy and Astrophysics. 411 (3): 559–564. arXiv:astro-ph/0308429. Bibcode:2003A&A...411..559K. doi:10.1051/0004-6361:20031378.
  11. ^ Eiroa, C.; et al. (July 2013). "DUst around NEarby Stars. The survey observational results". Astronomy & Astrophysics. 555: A11. arXiv:1305.0155. Bibcode:2013A&A...555A..11E. doi:10.1051/0004-6361/201321050.
  12. ^ "European Southern Observatory: Six Extrasolar Planets Discovered". SpaceRef.com. 7 August 2000. Retrieved 2009-08-02.
  13. ^ a b Plávalová, Eva; Solovaya, Nina A. (2013). "Analysis of the motion of an extrasolar planet in a binary system". The Astronomical Journal. 146 (5): 108. arXiv:1212.3843. Bibcode:2013AJ....146..108P. doi:10.1088/0004-6256/146/5/108.

External links[edit]

Coordinates: Sky map 03h 12m 46.4365s, −01° 11′ 45.964″