Location of β Trianguli (circled) | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 02 09 32.62712 |
| Declination | +34° 59′ 14.2694″ |
| Apparent magnitude (V) | +3.00 (3.44 + 4.19) |
| Characteristics | |
| Spectral type | A8III + A3III |
| U−B color index | +0.11 |
| B−V color index | +0.14 |
| Astrometry | |
| Radial velocity (Rv) | +9.9 km/s |
| Proper motion (μ) | RA: 149.16 mas/yr Dec.: –39.10 mas/yr |
| Parallax (π) | 25.71 ± 0.34 mas |
| Distance | 127 ± 2 ly (38.9 ± 0.5 pc) |
| Absolute magnitude (MV) | +0.05 |
| Orbit | |
| Period (P) | 31.3884 d |
| Eccentricity (e) | 0.53 |
| Periastron epoch (T) | 2432004.255 JD |
| Argument of periastron (ω) (secondary) | 318.4° |
| Semi-amplitude (K1) (primary) | 33.3 km/s |
| Semi-amplitude (K2) (secondary) | 69.2 km/s |
| Details | |
| A | |
| Mass | 2.6±0.3 M☉ |
| Radius | 4.38 R☉ |
| Luminosity | 60 L☉ |
| Surface gravity (log g) | 3.70 cgs |
| Temperature | 7,683 K |
| Rotational velocity (v sin i) | 70 km/s |
| Age | 0.40 Gyr |
| B | |
| Mass | 2.25±0.05 M☉ |
| Radius | 2.44 R☉ |
| Luminosity | 32 L☉ |
| Temperature | 8,759 K |
| Other designations | |
| β Trianguli, β Tri, Beta Tri, 4 Trianguli, HR 622, HD 13161, BD+34°381, FK5 75, HIP 10064, SAO 55306. | |
| Database references | |
| SIMBAD | data |
Beta Trianguli (Beta Tri, β Trianguli, β Tri) is the Bayer designation for a binary star system in the constellation Triangulum, located about 127 light years from Earth. Although it is only a third-magnitude star, it is the brightest star in the constellation Triangulum.
This is a double-lined spectroscopic binary star system with an orbital period of 31.39 days and an eccentricity of 0.53. The members are separated by a distance of less than 5 AU. The primary component has a stellar classification of A5IV, indicating that it has evolved away from the main sequence and is now a subgiant star. However, the classification is uncertain and not consistent with the mass derived from the orbit. It is among the least variable of the stars that were observed by the Hipparcos spacecraft, with a magnitude varying by only 0.0005.
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. It is thought to extend from 50 to 400 AU away from the stars.
Naming
- In combination with Alpha Trianguli, these stars were called Al Mīzān, which is Arabic for "The Scale Beam".
- In Chinese, 天大將軍 (Tiān Dà Jiāng Jūn), 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 天大將軍九 (Tiān Dà Jiāng Jūn jiǔ, English: the Ninth Star of Heaven's Great General.).
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.
- ^ 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
- ^ 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.
- Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W
- 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.
- ^ 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.
- 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.
- 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
- "bet Tri -- Spectroscopic binary", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-12
- 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
- ^ Garfinkle, Robert A. (1997), Star-Hopping: Your Visa to Viewing the Universe, Cambridge University Press, p. 238, ISBN 0-521-59889-3
- ^ 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.
- ^ 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.
- 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
- (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日 Archived 2011-07-16 at the Wayback Machine
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