Beta Trianguli
Beta Trianguli, formally named Alaybasan (for component A),[10] is a binary star[11] system in the constellation Triangulum, located about 127 light years from Earth.[1] Although it is only a third-magnitude star,[2] it is the brightest star in the constellation Triangulum.[12]
Naming
Beta Trianguli (Latinized from β Trianguli, abbreviated Beta Tri, β Tri) is the star's Bayer designation.
This star together with α Trianguli were called by the Arabic names Al Mīzān, "the Scale Beam",[12] and Al-Aybasān, "the Two Joints [of Aries]"; the latter also written as Al-Anīsān, meaning "the Two Friends".[10] Mizan has been used as a name for β Trianguli.[13] The name Alaybasan was approved for Beta Trianguli A by the IAU Working Group on Star Names on 7 November 2025 and it is now so entered in the IAU Catalog of Star Names.[14]
In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Heaven's Great General, refers to an asterism consisting of β Trianguli, γ Andromedae, φ Persei, 51 Andromedae, 49 Andromedae, χ Andromedae, υ Andromedae, τ Andromedae, 56 Andromedae, γ Trianguli and δ Trianguli. Consequently, the Chinese name for β Trianguli itself is Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx).[15]
Star system
This is a double-lined spectroscopic binary star system with an orbital period of 31.39 days and an eccentricity of 0.53.[6] The members are separated by a distance of 0.33 AU. The primary and secondary components have stellar classifications of A8III and A3III respectively, indicating that they evolved away from the main sequence and are now giant stars. Component A is 2.6 times more massive than the Sun, but expanded to Template:Solar radius calculator the Sun's radius[a] and irradiates 60 times more than the Sun. Component B is somewhat smaller and less luminous, being 2.25 times more massive, Template:Solar radius calculator times larger[b] and 30 times brighter than the Sun. The system has an age around 400 million years, less than 10% that of the Solar System.[3] Beta Trianguli is among the least variable of the stars that were observed by the Hipparcos spacecraft, with a magnitude varying by only 0.0005.[16]
Based on observations using the Spitzer Space Telescope, as reported in 2005, this system is emitting an excess of infrared radiation. This emission can be explained by a circumbinary ring of dust. The dust is emitting infrared radiation at a blackbody temperature of 100 K.[17] It is thought to extend from 50 to 400 AU away from the stars.[18]
See also
Notes
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- ^ a b Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
- ^ a b Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
References
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- ^ a b c d e Page Module:Citation/CS1/styles.css has no content.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
- ^ a b c Page Module:Citation/CS1/styles.css has no content.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 e f g Page Module:Citation/CS1/styles.css has no content.Piccotti, Luca; Docobo, José Ángel; Carini, Roberta; Tamazian, Vakhtang S.; Brocato, Enzo; Andrade, Manuel; Campo, Pedro P. (2020-02-01), "A study of the physical properties of SB2s with both the visual and spectroscopic orbits", Monthly Notices of the Royal Astronomical Society, 492 (2): 2709–2721, Bibcode:2020MNRAS.492.2709P, doi:10.1093/mnras/stz3616, ISSN 0035-8711 Beta Trianguli's database entry at VizieR.
- ^ Page Module:Citation/CS1/styles.css has no content.Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W
- ^ Page Module:Citation/CS1/styles.css has no content.Groenewegen, M. A. T. (2023-01-01), "Orbital parallax of binary systems compared to Gaia DR3 and the parallax zero-point offset at bright magnitudes", Astronomy and Astrophysics, 669: A4, arXiv:2210.14734, Bibcode:2023A&A...669A...4G, doi:10.1051/0004-6361/202244479, ISSN 0004-6361 Beta Trianguli's database entry.
- ^ a b Page Module:Citation/CS1/styles.css has no content.Pourbaix, D.; et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
- ^ Page Module:Citation/CS1/styles.css has no content.Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Robinson, P. E. (2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I". The Astronomical Journal. 126 (4): 2048. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365. S2CID 119417105.
- ^ Page Module:Citation/CS1/styles.css has no content.Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393 (3): 897–911, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943, S2CID 14070763
- ^ Page Module:Citation/CS1/styles.css has no content."bet Tri -- Spectroscopic binary", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-12
- ^ a b Page Module:Citation/CS1/styles.css has no content."Alaybasān (الأيبسان)". All Skies Encyclopaedia. IAU Working Group on Star Names. Retrieved 9 November 2025.
- ^ Page Module:Citation/CS1/styles.css has no content.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 Page Module:Citation/CS1/styles.css has no content.Garfinkle, Robert A. (1997), Star-Hopping: Your Visa to Viewing the Universe, Cambridge University Press, p. 238, ISBN 0-521-59889-3
- ^ Page Module:Citation/CS1/styles.css has no content.Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), Jet Propulsion Laboratory, California Institute of Technology.
- ^ Page Module:Citation/CS1/styles.css has no content."IAU Catalog of Star Names". Retrieved 13 November 2025.
- ^ Template:In lang AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日 Script error: No such module "webarchive".
- ^ Page Module:Citation/CS1/styles.css has no content.Adelman, S. J. (February 2001), "Research Note Hipparcos photometry: The least variable stars", Astronomy and Astrophysics, 367 (1): 297–298, Bibcode:2001A&A...367..297A, doi:10.1051/0004-6361:20000567
- ^ Page Module:Citation/CS1/styles.css has no content.Stansberry, J. A.; et al. (2005). "A Spitzer Survey for Debris Disks in Binary Star Systems". Protostars and Planets V, Proceedings of the Conference held October 24-28, 2005, in Hilton Waikoloa Village, Hawai'i. p. 8613. Bibcode:2005prpl.conf.8613S.
- ^ Page Module:Citation/CS1/styles.css has no content.Kennedy, G. M.; Wyatt, M. C.; Sibthorpe, B.; Phillips, N. M.; Matthews, B.; Greaves, J. S. (2012). "Coplanar Circumbinary Debris Disks". Monthly Notices of the Royal Astronomical Society. 426 (3): 2115–28. arXiv:1208.1759. Bibcode:2012MNRAS.426.2115K. doi:10.1111/j.1365-2966.2012.21865.x. S2CID 59408005.
