94 Ceti
Trinary star system in the constellation Cetus
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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[1] |
| Right ascension | 03h 12m 46.43719s[2] |
| Declination | −01° 11′ 45.9613″[2] |
| Apparent magnitude (V) | +5.070[3] |
| Characteristics | |
| Spectral type | F8V / M3V / M[citation needed] |
| U−B color index | +0.09[4] |
| B−V color index | +0.56[4] |
| Astrometry | |
| Radial velocity (Rv) | +18.96 ± 0.08[5] km/s |
| Proper motion (μ) | RA: 194.56[2] mas/yr Dec.: −69.01[2] mas/yr |
| Parallax (π) | 44.29±0.28 mas[2] |
| Distance | 73.6 ± 0.5 ly (22.6 ± 0.1 pc) |
| Absolute magnitude (MV) | +3.3[1] |
| Orbit[6] | |
| Primary | 94 Ceti A |
| Name | 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[7] | |
| Primary | 94 Ceti B |
| Name | 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[8] M☉ |
| Radius | 1.898 ± 0.070[9] R☉ |
| Luminosity | 4.02 ± 0.05[10] L☉ |
| Surface gravity (log g) | 3.98 ± 0.10[8] cgs |
| Temperature | 6,055 ± 10.0[11] K |
| Metallicity [Fe/H] | 1.15 ± 0.07[8] dex |
| Rotation | 12.2 d[12] |
| Rotational velocity (v sin i) | 8.4 ± 0.8[8] km/s |
| Age | 4.8[10] Gyr |
| Other designations | |
| BD−01°457, FK5 116, GJ 128, HD 19994, HIP 14954, HR 962, LTT 1515, SAO 130355 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | 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.[13]
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.[6]
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.[14] It is most stable if its inclination is either 65 or 115, ± 3.[15]
| 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 | — | — |