Jump to content

Psi Andromedae

From Wikipedia, the free encyclopedia
(Redirected from 20 And)
Psi Andromedae
Diagram showing star positions and boundaries of the Andromeda constellation and its surroundings
Location of ψ Andromedae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 46m 02.04703s[1]
Declination +46° 25′ 12.9865″[1]
Apparent magnitude (V) 4.95[2]
Characteristics
Spectral type G5 Ib[3] + B9[4]
U−B color index +0.83[2]
B−V color index +1.085[3]
Astrometry
Radial velocity (Rv)-23.62[3] km/s
Proper motion (μ) RA: 8.446(132)[1] mas/yr
Dec.: −7.143(109)[1] mas/yr
Parallax (π)1.6352 ± 0.1627 mas[1]
Distance2,000 ± 200 ly
(610 ± 60 pc)
Absolute magnitude (MV)–3.039[3]
Details
ψ And A
Mass5.4[4] M
Radius47.58[5] R
Luminosity1,049±161[5] L
Surface gravity (log g)1.50[3] cgs
Temperature4,990[3] K
Metallicity [Fe/H]+0.10[3] dex
Age79[4] Myr
B
Mass2.6[4] M
Temperature11,000[4] K
Other designations
20 And, BD+45° 4321, FK5 1622, HD 223047, HIP 117221, HR 9003, SAO 53355, PPM 64635[6]
Database references
SIMBADdata

Psi Andromedae (ψ And, ψ Andromedae) is the Bayer designation for a triple star[4] system in the northern constellation of Andromeda. The combined apparent visual magnitude of this system is 4.95.[2] Based upon parallax measurements, is roughly 2,000 light-years (610 parsecs) from Earth.[1]

The primary component has a stellar classification of G5 Ib,[3] which matches the spectrum of an evolved supergiant star. It forms a pair with a star of type B9 with an unknown luminosity class separated by 0.28 arcseconds. A third component has a separation of 0.14 arcseconds. Details of the orbital arrangement remain uncertain.[4]

Naming

[edit]

In Chinese, 螣蛇 (Téng Shé), meaning Flying Serpent, refers to an asterism consisting of ψ Andromedae, α Lacertae, 4 Lacertae, π2 Cygni, π1 Cygni, HD 206267, ε Cephei, β Lacertae, σ Cassiopeiae, ρ Cassiopeiae, τ Cassiopeiae, AR Cassiopeiae, 9 Lacertae, 3 Andromedae, 7 Andromedae, 8 Andromedae, λ Andromedae, κ Andromedae and ι Andromedae,. Consequently, the Chinese name for ψ Andromedae itself is 螣蛇二十 (Téng Shé èrshí, English: the Twentieth of Flying Serpent).[7]

References

[edit]
  1. ^ a b c d e f 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.
  2. ^ a b c Argue, A. N. (1966), "UBV photometry of 550 F, G and K type stars", Monthly Notices of the Royal Astronomical Society, 133 (4): 475–493, Bibcode:1966MNRAS.133..475A, doi:10.1093/mnras/133.4.475.
  3. ^ a b c d e f g h Soubiran, C.; et al. (March 2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics, 480 (1): 91–101, arXiv:0712.1370, Bibcode:2008A&A...480...91S, doi:10.1051/0004-6361:20078788, S2CID 16602121.
  4. ^ a b c d e f g Parsons, Sidney B. (May 2004), "New and Confirmed Triple Systems with Luminous Cool Primaries and Hot Companions", The Astronomical Journal, 127 (5): 2915–2930, Bibcode:2004AJ....127.2915P, doi:10.1086/383546.
  5. ^ a b McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. ISSN 0035-8711. Psi Andromedae's database entry at VizieR.
  6. ^ "* psi And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 28 January 2018.
  7. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 7 日