Binary star system in the constellation Andromeda
Pi Andromedae
Location of π Andromedae (circled)
Observation dataEpoch J2000 Equinox J2000
Constellation
Andromeda
Right ascension 00h 36m 52.85132s [ 1]
Declination
+33° 43′ 09.6363″[ 1]
Apparent magnitude (V)4.36[ 2] [ 3]
Characteristics
Spectral type
B5 V[ 4] B5 V + B5 V [ 3]
U−B color index
–0.55[ 2]
B−V color index
–0.16[ 2]
Astrometry Radial velocity (Rv )+8.7[ 5] km/s Proper motion (μ) RA: mas /yr [ 1] Dec.: mas /yr [ 1] Parallax (π)5.6563± 0.1474 mas [ 1] Distance 580 ± 20 ly pc ) Orbit [ 6] Period (P)± 0.06 dSemi-major axis (a)± 0.05 mas Eccentricity (e)0.542± 0.006 Inclination (i)103.0± 0.2° Longitude of the node (Ω)94.7± 0.2° Periastron epoch (T)7717.7± 0.4 Argument of periastron (ω)170.7± 0.7° Semi-amplitude 1 )47.50± 0.53 km/s Semi-amplitude (K2 )117.4± 2.8 km/s Details[ 7] A Mass 5.8[ 6] M ☉ Radius 4.7 R ☉ Luminosity 1,000 L ☉ Surface gravity (log g )4.10[ 4] cgs Temperature 15,000 K Metallicity [Fe/H] –0.20[ 4] dex Rotational velocity (v sin i )25[ 8] Age 80 Myr B Mass 4.8[ 6] M ☉ Radius 4.7 R ☉ Luminosity 1,000 L ☉ Temperature 15,000 K Other designations Pi And, π Andromedae, π And , 29 Andromedae , BD +32°101FK5 18HD 3369HIP 2912HR 154SAO 54033PPM 65480ADS 513Database references SIMBAD data
Pi Andromedae is a binary star [ 3] constellation of Andromeda . Its Bayer designation is latinized from π Andromedae , and abbreviated Pi And or π And , respectively. With an apparent visual magnitude of 4.4,[ 2] visible to the naked eye . Based on parallax measurements, it is located at a distance of approximately 580 light-years (180 parsecs ) from Earth .[ 1]
π Andromedae in optical light The pair is classified as a blue-white B-type main sequence dwarf , with an apparent magnitude of +4.34. It is a spectroscopic binary with an orbital period of 143.5 days and an eccentricity of 0.54.[ 6]
The spectroscopic binary forms a triple system with BD+32 102 , a magnitude 8.6 star located 35.9 arcseconds away.[ 3] arcseconds separation is an 11th magnitude companion that is just located on the same line of sight, but at a very different distance from us.
Naming
In Chinese , 奎宿 Kuí Sù Legs (asterism)η Andromedae , 65 Piscium , ζ Andromedae , ε Andromedae , δ Andromedae , ν Andromedae , μ Andromedae , β Andromedae , σ Piscium , τ Piscium , 91 Piscium , υ Piscium , φ Piscium , χ Piscium and ψ¹ Piscium . Consequently, the Chinese name for π Andromedae itself is 奎宿六 Kuí Sù liù the Sixth Star of Legs .)[ 9]
References
^ a b c d e Brown, A. G. A. ; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties" . Astronomy & Astrophysics 649 : A1. arXiv :2012.01533 Bibcode :2021A&A...649A...1G . doi :10.1051/0004-6361/202039657 S2CID 227254300 . (Erratum: doi :10.1051/0004-6361/202039657e ) . Gaia EDR3 record for this source at VizieR .^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory , 4 (99): 99, Bibcode :1966CoLPL...4...99J . ^ a b c d Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems" . Monthly Notices of the Royal Astronomical Society . 389 (2): 869– 879. arXiv :0806.2878 Bibcode :2008MNRAS.389..869E . doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ a b c Cenarro, A. J.; et al. (January 2007), "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters", Monthly Notices of the Royal Astronomical Society 374 (2): 664– 690, arXiv :astro-ph/0611618 Bibcode :2007MNRAS.374..664C , doi :10.1111/j.1365-2966.2006.11196.x S2CID 119428437 . ^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication , Washington: Carnegie Institution of Washington, Bibcode :1953GCRV..C......0W . ^ a b c d Hummel, C. A.; et al. (July 1995). "Orbits of Small Angular Scale Binaries Resolved with the Mark III Interferometer". Astronomical Journal . 110 : 376. Bibcode :1995AJ....110..376H . doi :10.1086/117528 . ^ "Pi And" . stars.astro.illinois.edu . Retrieved 2025-02-06 .^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal , 573 (1): 359– 365, Bibcode :2002ApJ...573..359A , doi :10.1086/340590 ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日 Archived 2016-03-03 at the Wayback Machine
External links
