Astronomy:Beta Trianguli
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 02h 09m 32.62712s[1] |
| Declination | +34° 59′ 14.2694″[1] |
| Apparent magnitude (V) | +3.00[2] (3.44 + 4.19)[3] |
| Characteristics | |
| Spectral type | A8III / A3III[3] |
| U−B color index | +0.11[2] |
| B−V color index | +0.21 / 0.07[3] |
| Astrometry | |
| Radial velocity (Rv) | +9.9[4] km/s |
| Proper motion (μ) | RA: 149.16[1] mas/yr Dec.: –39.10[1] mas/yr |
| Parallax (π) | 23.169 ± 0.434[5] mas |
| Distance | 141 ± 3 ly (43.2 ± 0.8 pc) |
| Absolute magnitude (MV) | −0.136 (0.305 + 0.1055)[3] |
| Orbit[6] | |
| Period (P) | 31.3884 d |
| Semi-major axis (a) | 0.330±0.005 astronomical unit|AU[3] |
| 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[3] | |
| A | |
| Mass | 3.52±0.27 M☉ |
| Radius | 4.38[lower-alpha 1] R☉ |
| Luminosity | 60.3+15.6 −12.4 L☉ |
| Surface gravity (log g) | 3.70[7] cgs |
| Temperature | 7,683 K |
| Rotational velocity (v sin i) | 70[8] km/s |
| Age | 0.40+0.23 −0.15 Gyr |
| B | |
| Mass | 1.37±0.09 M☉ |
| Radius | 2.44[lower-alpha 2] R☉ |
| Luminosity | 31.6+3.9 −3.4 L☉ |
| Temperature | 8,759 K |
| Age | 0.45+0.12 −0.09 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Beta Trianguli (Beta Tri, β Trianguli, β Tri) is the Bayer designation for a binary star[10] 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.[11]
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 astronomical unit|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 4.4 the Sun's radius[lower-alpha 1] and irradiates 60 times more than the Sun. Component B is somewhat smaller and less luminous, being 2.25 times more massive, 2.44 times larger[lower-alpha 2] 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.[12]
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.[13] It is thought to extend from 50 to 400 AU away from the stars.[14]
Naming
- In combination with Alpha Trianguli, these stars were called Al Mīzān, which is Arabic for "The Scale Beam".[11]
- 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.).[15]
See also
- Beta Trianguli Australis
- Alpheratz
- Sheratan
- Menkalinan
Notes
- ↑ 1.0 1.1 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:
- ↑ 2.0 2.1 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
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V
- ↑ 2.0 2.1 2.2 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
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 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, doi:10.1093/mnras/stz3616, ISSN 0035-8711, Bibcode: 2020MNRAS.492.2709P Beta Trianguli's database entry at VizieR.
- ↑ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington (Carnegie Institution of Washington), Bibcode: 1953GCRV..C......0W
- ↑ 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, doi:10.1051/0004-6361/202244479, ISSN 0004-6361, Bibcode: 2023A&A...669A...4G Beta Trianguli's database entry.
- ↑ 6.0 6.1 Pourbaix, D. et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics 424 (2): 727–732, doi:10.1051/0004-6361:20041213, Bibcode: 2004A&A...424..727P.
- ↑ 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. doi:10.1086/378365. Bibcode: 2003AJ....126.2048G.
- ↑ 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, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R
- ↑ "bet Tri -- Spectroscopic binary", SIMBAD (Centre de Données astronomiques de Strasbourg), https://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Trianguli, 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E
- ↑ 11.0 11.1 Garfinkle, Robert A. (1997), Star-Hopping: Your Visa to Viewing the Universe, Cambridge University Press, p. 238, ISBN 0-521-59889-3, https://books.google.com/books?id=40JzBYGREL0C&pg=PA238
- ↑ Adelman, S. J. (February 2001), "Research Note Hipparcos photometry: The least variable stars", Astronomy and Astrophysics 367 (1): 297–298, doi:10.1051/0004-6361:20000567, Bibcode: 2001A&A...367..297A
- ↑ Stansberry, J. A.; Stapelfeldt, K. R.; Trilling, D. T.; Su, K. Y.; Rieke, G. H.; Chen, C. (2005). "Protostars and Planets V, Proceedings of the Conference held October 24-28, 2005, in Hilton Waikoloa Village, Hawai'i". pp. 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. doi:10.1111/j.1365-2966.2012.21865.x. Bibcode: 2012MNRAS.426.2115K.
- ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日
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