 δ Arae (lower center) in the Ara Constellation | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ara |
| Right ascension | 17 31 05.91272 |
| Declination | –60° 41′ 01.8522″ |
| Apparent magnitude (V) | 3.62 |
| Characteristics | |
| Spectral type | B8 Vn + G8 V |
| U−B color index | –0.31 |
| B−V color index | –0.10 |
| Astrometry | |
| Radial velocity (Rv) | +10 km/s |
| Proper motion (μ) | RA: –54.01 mas/yr Dec.: –99.25 mas/yr |
| Parallax (π) | 16.48 ± 0.34 mas |
| Distance | 198 ± 4 ly (61 ± 1 pc) |
| Absolute magnitude (MV) | −0.31 |
| Details | |
| Mass | 3.56 M☉ |
| Radius | 3.12 ± 0.15 R☉ |
| Luminosity | 214 L☉ |
| Surface gravity (log g) | 3.81 ± 0.06 cgs |
| Temperature | 11,962 ± 86 K |
| Rotational velocity (v sin i) | 255 km/s |
| Age | 125 Myr |
| Other designations | |
| δ Ara, CPD –60° 6842, FK5 648, HD 158094, HIP 85727, HR 6500, SAO 253945. | |
| Database references | |
| SIMBAD | data |
Delta Arae, Latinized from δ Arae, is the Bayer designation for a double star in the southern constellation Ara. It has an apparent visual magnitude of 3.62 and is visible to the naked eye. Based upon an annual parallax of 16.48 mas, it is about 198 light-years (61 parsecs) distant from the Earth.
Delta Arae is massive B-type main sequence star with a stellar classification of B8 Vn. The 'n' suffix indicates the absorption lines are spread out broadly because the star is spinning rapidly. It has a projected rotational velocity of 255 km/s, resulting in an equatorial bulge with a radius 13% larger than the polar radius. It has a magnitude 9.5 companion G-type main sequence star that may form a binary star system with Delta Arae.
There is a 12th magnitude optical companion located 47.4 arcseconds away along a position angle of 313°.
Etymology
Delta Arae was known as 龜三 (meaning: "the 3rd (star) of Guī") in traditional Chinese astronomy.
Allen erroneously called both Delta and Zeta Arae "Tseen Yin" (天陰). He probably confused the constellation "Ara" with "Ari", as 天陰 is actually in Aries.
See also
References
- ^ 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.
- ^ Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
- ^ Houk, Nancy (1979), "Michigan catalogue of two-dimensional spectral types for the HD stars", Ann Arbor: Dept. Of Astronomy, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.
- Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
- ^ 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.
- ^ Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue", The Astrophysical Journal Supplement, 192 (1): 2, arXiv:1007.0425, Bibcode:2011ApJS..192....2S, doi:10.1088/0067-0049/192/1/2, S2CID 119226823.
- ^ Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal, 129 (3): 1642–1662, arXiv:astro-ph/0412542, Bibcode:2005AJ....129.1642F, doi:10.1086/427855, S2CID 119512018.
- ^ Ehrenreich, D.; et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics, 523: A73, arXiv:1007.0002, Bibcode:2010A&A...523A..73E, doi:10.1051/0004-6361/201014763, S2CID 54913363.
- "del Ara". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-27.
{{cite web}}: CS1 maint: postscript (link) - ^ Chevalier, S., and Tsuchihashi, P., (1911): "Catalogue d'Étoiles fixes, observés a Pekin sous l'Empereur Kien Long (Qianlong (Chien-Lung)), XVIII siecle", Annales de l'Observatoire Astronomique de Zô-Sé.
- ^ 伊世同 (Yi Shi Tong) (1981): 『中西対照恒星図表』科学出版社.(in Chinese)
- Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 64. ISBN 0-486-21079-0.
Further reading
- 大崎正次 (1987): 「中国の星座・星名の同定一覧表」『中国の星座の歴史』 雄山閣出版, pp. 312, 328.(in Japanese)
External links
- HR 6500
- AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 1 日 Archived 2011-09-28 at the Wayback Machine(in Chinese)
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