Astronomy:112 Piscium
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pisces[1] |
| Right ascension | 02h 00m 09.15955s[2] |
| Declination | +03° 05′ 49.2504″[2] |
| Apparent magnitude (V) | 5.89[1] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G2IV[3] or G0V[1] |
| B−V color index | 0.610[1] |
| Astrometry | |
| Radial velocity (Rv) | −18.50±0.14[2] km/s |
| Proper motion (μ) | RA: +230.826[2] mas/yr Dec.: −256.471[2] mas/yr |
| Parallax (π) | 31.4492 ± 0.0566[2] mas |
| Distance | 103.7 ± 0.2 ly (31.80 ± 0.06 pc) |
| Absolute magnitude (MV) | 3.27[1] |
| Details | |
| Mass | 1.100±0.134[4] M☉ |
| Radius | 1.80±0.06[5] R☉ |
| Luminosity | 3.74[2] L☉ |
| Surface gravity (log g) | 4.03±0.10[5] cgs |
| Temperature | 5967±70[5] K |
| Metallicity [Fe/H] | +0.21±0.07[5] dex |
| Rotational velocity (v sin i) | 4.8±0.6[5] km/s |
| Age | 5.9[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | 12235 data |
| ARICNS | data |
112 Piscium, also named Zibbatu,[7] is a star 103.7 light-years (31.8 parsecs) away in the constellation Pisces. With an apparent magnitude of 5.9, it is faintly visible to the naked eye under good viewing conditions. It appears near the brighter star Alpha Piscium (Alrescha) in the sky; the two are about 35′ apart.[6]
Nomenclature
112 Piscium is the star's Flamsteed designation; other designations include HD 12235 in the Henry Draper Catalogue.[6] The Akkadian zibbātu "tails" is a Babylonian name for the constellation Pisces, which was originally visualized as the tails of a swallow (SIM.MAḪ). The IAU Working Group on Star Names adopted the name Zibbatu for 112 Piscium on 17 September 2026.[7]
Properties
The stellar classification of 112 Piscium is G2IV,[3] indicating that it is a G-type subgiant star that has evolved off the main sequence. Other sources classify it as G0V,[1] matching a main-sequence star. Gaia DR3 supports a subgiant classification.[2][8] This star has about 1.1 times the mass[4] and 1.8 times the radius of the Sun,[5] and is radiating 3.7 times the Sun's luminosity[2] from its photosphere at an effective temperature of 5967 K. Classified as a population I star, it is older than the Sun and has a somewhat higher metallicity (abundance of elements heavier than helium).[5] It is thought to be a member of the HR 1614 group of stars that share a common motion through space.[9]
Planetary system
Two planetary companions to this star (HD 12235) were detected in 2022 using both radial velocity and astrometry.[4] A companion was previously suspected.[5] The inner planet has a minimum mass of about 10 Earth masses, making it a sub-Neptune; it orbits close to its star with a period of just 4.4 days. The outer planet is a super-Jupiter about 10 times the mass of Jupiter; it has a wide orbit with a period of about 100 years.[4][10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥10+1 −2 M⊕ |
0.054±0.002 | 4.36305+0.00025 −0.00042 |
0.38+0.11 −0.25 |
— | — |
| c | 9.9+3.2 −1.8 MJ |
22.2+3.9 −2.8 |
36,337+9,732 −6,059 |
0.17+0.11 −0.15 |
47.7+12.7 −11.8° |
— |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 Cowley, A. P.; Bidelman, W. P. (February 1979). "MK spectral types for some F and G stars." (in en). Publications of the Astronomical Society of the Pacific 91: 83. doi:10.1086/130446. ISSN 0004-6280. Bibcode: 1979PASP...91...83C.
- ↑ 4.0 4.1 4.2 4.3 Feng, Fabo; Butler, R. Paul et al. (September 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series 262 (1): 21. doi:10.3847/1538-4365/ac7e57. ISSN 0067-0049. Bibcode: 2022ApJS..262...21F.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Fuhrmann, Klaus; Chini, Rolf (March 2021). "On ancient solar-type stars – II" (in en). Monthly Notices of the Royal Astronomical Society 501 (4): 4903–4916. doi:10.1093/mnras/staa3942. ISSN 0035-8711. Bibcode: 2021MNRAS.501.4903F.
- ↑ 6.0 6.1 6.2 "* 112 Psc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+112+Psc.
- ↑ 7.0 7.1 "IAU Catalog of Star Names". https://exopla.net/star-names/modern-iau-star-names/.
- ↑ "Astrophysical parameter tables [Gaia DR3 documentation"]. ESA. https://gea.esac.esa.int/archive/documentation/GDR3/Gaia_archive/chap_datamodel/sec_dm_astrophysical_parameter_tables/ssec_dm_astrophysical_parameters.html#astrophysical_parameters-evolstage_flame.
- ↑ Eggen, O. J. (November 1992). "HR 1614 and the dissolution of a supercluster". The Astronomical Journal 104: 1906. doi:10.1086/116366. Bibcode: 1992AJ....104.1906E.
- ↑ 10.0 10.1 "HD 12235 Overview". NASA Exoplanet Archive. https://exoplanetarchive.ipac.caltech.edu/overview/HD%2012235.
 |  |
