Pi Arietis

π Arietis
Location of π Arietis (circled)
Observation data
Epoch J2000      Equinox ICRS
Constellation Aries
Right ascension 02h 49m 17.55924s
Declination +17° 27′ 51.5168″
Apparent magnitude (V) 5.314
Characteristics
Spectral type B6 V + A0 V + F8 V
U−B color index −0.47
B−V color index −0.06
Astrometry
Radial velocity (Rv)+8.8±0.9 km/s
Proper motion (μ) RA: +2.60 mas/yr
Dec.: −14.10 mas/yr
Parallax (π)4.18±0.69 mas
Distanceapprox. 800 ly
(approx. 240 pc)
Absolute magnitude (MV)−1.56
Details
Mass4.4+0.55
−0.51 M☉
Luminosity538 L☉
Surface gravity (log g)4.5±0.25 cgs
Temperature16,000±1,000 K
Rotational velocity (v sin i)70 km/s
Age13+9
−6 Myr
Other designations
π Ari, 42 Arietis, NSV 944, BD+16°355, GC 3378, HD 17543, HIP 13165, HR 836, SAO 93127, PPM 118581
Database references
SIMBADdata

Pi Arietis is a multiple star system in the northern constellation of Aries. Its name is a Bayer designation that is Latinized from π Arietis, and abbreviated Pi Ari or π Ari. Based upon parallax measurements made during the Hipparcos mission, this system is approximately 800 light-years (250 parsecs) distant from Earth, and has an apparent visual magnitude of 5.314. This is bright enough to be faintly seen with the naked eye. The position of this system near the ecliptic means it is subject to lunar occultation.

The primary member of this system is an intermediate-mass, B-type main sequence star with a stellar classification of B6 V. It is a close, single-lined spectroscopic binary with an orbital period of 3.854 days, an eccentricity of 0.04, and a combined visual magnitude of 5.30. At an angular separation of 3.28 arcseconds is a magnitude 8.46 A-type main sequence star with a classification of A0 Vp. Finally, a fourth member of the system is a magnitude 11.0 F-type main sequence star with a classification of F8V at an angular separation of 25.2 arcseconds from the primary.

Name

This star, along with δ Ari, ε Ari, ζ Ari, and ρ3 Ari, were Al Bīrūnī's Al Buṭain (ألبطين), the dual of Al Baṭn, the Belly. According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Buṭain were the title for five stars : δ Ari as Botein, π Ari as Al Buṭain I, ρ3 Ari as Al Buṭain II, ε Ari as Al Buṭain III dan ζ Ari as Al Buṭain IV.

In Chinese, 左更 (Zuǒ Gēng), meaning Official in Charge of the Forest, refers to an asterism consisting of π Arietis, ν Arietis, μ Arietis, ο Arietis and σ Arietis. Consequently, the Chinese name for π Arietis itself is 左更五 (Zuǒ Gēng wu, English: the Fifth Star of Official in Charge of the Forest.)

References

  1. 1 2 3 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. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 van Leeuwen, F. (November 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.
  3. 1 2 3 4 5 6 7 Gullikson, Kevin; et al. (August 2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", The Astronomical Journal, 152 (2): 13, arXiv:1604.06456, Bibcode:2016AJ....152...40G, doi:10.3847/0004-6256/152/2/40, S2CID 119179065, 40.
  4. 1 2 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.
  5. 1 2 Crawford, D. L.; et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal, 76: 1058, Bibcode:1971AJ.....76.1058C, doi:10.1086/111220.
  6. ↑ 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.
  7. ↑ Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
  8. ↑ "pi. Ari". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-07.
  9. ↑ Herr, Richard B. (April 1969), "Identification List of Spectroscopic and Eclipsing Binaries Subject to Occultations by the Moon", Publications of the Astronomical Society of the Pacific, 81 (479): 105, Bibcode:1969PASP...81..105H, doi:10.1086/128748.
  10. ↑ Chini, R.; et al. (2012), "A spectroscopic survey on the multiplicity of high-mass stars", Monthly Notices of the Royal Astronomical Society, 424 (3): 1925–1929, arXiv:1205.5238, Bibcode:2012MNRAS.424.1925C, doi:10.1111/j.1365-2966.2012.21317.x, S2CID 119120749.
  11. ↑ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc, p. 83, ISBN 0-486-21079-0, retrieved 2010-12-12.{{citation}}: CS1 maint: ignored ISBN errors (link)
  12. ↑ Rhoads, Jack W. (November 15, 1971), "Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars", Jet Propulsion Laboratory, California Institute of Technology, retrieved 2025-05-07.
  13. ↑ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  14. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 21 日 Archived 2011-05-22 at the Wayback Machine