94 Ceti
94 Ceti (HD 19994) is a trinary star system approximately 73 light-years away in the constellation Cetus.
| 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] |
| Characteristics | |
| Spectral type | F8V / M3V / M |
| U−B color index | +0.09[3] |
| B−V color index | +0.56[3] |
| Astrometry | |
| 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 |
| Distance | 73.6 ± 0.5 ly (22.6 ± 0.1 pc) |
| Absolute magnitude (MV) | 3.32 |
| Orbit[5] | |
| Primary | 94 Ceti A |
| Companion | 94 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) (secondary) | 342±7° |
| Orbit[6] | |
| Primary | 94 Ceti B |
| Companion | 94 Ceti C |
| Period (P) | 378.35+0.36 −0.34 d |
| Semi-major axis (a) | 0.984±0.007 AU |
| Eccentricity (e) | 0.360±0.005 |
| Inclination (i) | 108.323+0.581 −0.561° |
| Longitude of the node (Ω) | 191.496+1.602 −1.562° |
| Periastron epoch (T) | MJD 55113.904±0.220 |
| Argument of periastron (ω) (secondary) | 334.895±0.240° |
| Details | |
| Mass | 1.30[7] M☉ |
| Radius | 1.898 ± 0.070[8] R☉ |
| Luminosity | 4.02 ± 0.05[9] L☉ |
| Surface gravity (log g) | 3.98 ± 0.10[7] cgs |
| Temperature | 6,055 ± 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 |
| Age | 4.8[9] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
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
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
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]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.855 ± 0.045 MJ | 1.427 | 535.7 ± 3.1 | 0.30 ± 0.04 | — | — |
See also
References
- 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. S2CID 18759600. Vizier catalog entry
- 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.
- Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- 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. S2CID 51814894.
- 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. S2CID 55234970.
- Röll, Tristan Alexander (2011). Astrometric search for extrasolar planets in stellar multiple systems (PhD). Friedrich-Schiller-University Jena.
- 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.
- 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. S2CID 18370219.
- 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, S2CID 14911430, 40. See Table 3.
- 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. S2CID 18478960.
- 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. S2CID 377244.
- "European Southern Observatory: Six Extrasolar Planets Discovered". SpaceRef.com. 7 August 2000. Retrieved 2 August 2009.
- 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. S2CID 118629538.
External links
- SolStation: 94 Ceti 2 + orbits
- 94 Ceti by Professor Jim Kaler.
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