Star in the constellation Pisces
33 Piscium The narrow triangle in which this comparative star, in apparent magnitude (brightness viewed from Earth), figures. Click to show context
Observation dataEpoch J2000 Equinox J2000 Constellation Pisces Right ascension 00h 05m 20.14193s [ 1] Declination −05° 42′ 27.4279″[ 1] Apparent magnitude (V)4.61[ 2] Characteristics Spectral type K0 IIIb[ 3] Apparent magnitude (U)6.52[ 2] Apparent magnitude (B)5.65[ 2] Apparent magnitude (R)3.83[ 2] Apparent magnitude (I)3.29[ 2] Apparent magnitude (J)2.89[ 2] Apparent magnitude (H)2.31[ 2] Apparent magnitude (K)2.21[ 2] B−Vcolor index ± 0.037Variable type RS CVn [ 3] Astrometry Radial velocity (Rv )± 0.23[ 4] km/s Proper motion (μ)RA: −6.54[ 1] mas /yr Dec.: 87.85[ 1] mas /yr Parallax (π)25.32± 0.53 mas [ 1] Distance 129 ± 3 ly pc ) Absolute magnitude (MV )1.63[ 5] Orbit [ 6] Period (P)72.93 d Eccentricity (e)± 0.017Periastron epoch (T)± 0.809 JDArgument of periastron (ω)± 4.60Semi-amplitude 1 )± 0.31Details[ 7] Mass ± 0.22M ☉ Radius 7[ 8] R ☉ Luminosity 24[ 8] L ☉ Surface gravity (log g )± 0.11cgs Temperature ± 92K Metallicity [Fe/H] ± 0.05dex Rotational velocity (v sin i )0.0[ 8] Age +3.3 Myr Other designations 33 Psc ,BC Psc ,BD −06° 6357FK5 1002GC 59HD 28HIP 443HR 3SAO 128572PPM 181831GCRV 36GSC 04669-009962MASS J00052013-0542275[ 9] Database references SIMBAD data
33 Piscium is abinary star system in thezodiac constellation ofPisces . It is visible to the naked eye with anapparent visual magnitude of 4.61.[ 2] parallax shift of± 0.53 mas [ 1] light years . It is moving closer to the Sun with a heliocentricradial velocity of −6.6 km/s.[ 4]
This system was found to have a variable radial velocity byLeah B. Allen and Adelaide Hobe ofLick Observatory in 1911.[ 10] spectroscopic binary , and theorbital elements were published by Canadian astronomerW. E. Harper in 1926.[ 3] orbital period of 72.93 days and aneccentricity of 0.27.[ 6] RS Canum Venaticorum variable ,[ 3] star spots , and has thevariable star designation BC Psc.[ 11]
The primary, component A, is a first-ascentred giant with astellar classification of K0 IIIb, having chemical abundances that match a firstdredge-up mixing model. Pourbaix & Boffin (2003) estimated the mass of the primary as± 0.4 M ☉ ± 0.11 M ☉ [ 3] ± 0.22 M ☉ [ 7] [ 7] [ 8] [ 8] Sun's luminosity from itsphotosphere at aneffective temperature of about 4,736 K.[ 7]
^a b c d e f 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 . ^a b c d e f g h i Ducati, J. R. (2002), "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system",VizieR On-line Data Catalog ,2237 ,Bibcode :2002yCat.2237....0D . ^a b c d e Barisevičius, G.; et al. (2011), "Chemical Composition of the RS CVn-type Star 33 Piscium",Baltic Astronomy ,20 :53– 63,arXiv :1105.5650 Bibcode :2011BaltA..20...53B ,doi :10.1515/astro-2017-0268 ,S2CID 118081703 . ^a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project",Astronomy & Astrophysics ,546 : 14,arXiv :1208.3048 Bibcode :2012A&A...546A..61D ,doi :10.1051/0004-6361/201219219 ,S2CID 59451347 , A61. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation",Astronomy Letters ,38 (5): 331,arXiv :1108.4971 Bibcode :2012AstL...38..331A ,doi :10.1134/S1063773712050015 ,S2CID 119257644 . ^a b Harper, W. E. (October 1926), "Two K-type spectroscopic binaries",Publications of the Dominion Observatory Ottawa ,3 :341– 348,Bibcode :1926PDAO....3..341H . ^a b c d Feuillet, Diane K.; et al. (2016), "Determining Ages of APOGEE Giants with Known Distances",The Astrophysical Journal ,817 (1): 15,arXiv :1511.04088 Bibcode :2016ApJ...817...40F ,doi :10.3847/0004-637X/817/1/40 S2CID 118675933 , 40. ^a b c d e Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity",The Astronomical Journal ,135 (1):209– 231,Bibcode :2008AJ....135..209M ,doi :10.1088/0004-6256/135/1/209 S2CID 121883397 . ^ "33 Psc" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2018-03-12 .^ Campbell, William Wallace; et al. (1911), "Sixty-eight stars whose radial velocities vary",Lick Observatory Bulletin ,199 :140– 154,Bibcode :1911LicOB...6..140C ,doi :10.5479/ADS/bib/1911LicOB.6.140C . ^ Kazarovets, E. V.; Samus, N. N. (October 1990), "The 70th Name-List of Variable Stars",Information Bulletin on Variable Stars ,3530 : 1,Bibcode :1990IBVS.3530....1K .
