Beta Trianguli

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Beta Trianguli
Diagram showing star positions and boundaries of the Triangulum constellation and its surroundings
Cercle rouge 100%.svg
Location of β Trianguli (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Triangulum
Right ascension 02h 09m 32.62712s[1]
Declination +34° 59′ 14.2694″[1]
Apparent magnitude (V) +3.00[2]
Characteristics
Spectral type A5IV[3]
U−B color index +0.11[2]
B−V color index +0.14[2]
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)25.71 ± 0.34[1] mas
Distance127 ± 2 ly
(38.9 ± 0.5 pc)
Absolute magnitude (MV)+0.05[5]
Orbit[6]
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
Mass3.5[7] M
Luminosity74 (combined)[7] L
Surface gravity (log g)3.70[3] cgs
Temperature8,186[3] K
Rotational velocity (v sin i)70[8] km/s
Age0.73[9] Gyr
Other designations
β Trianguli, β Tri, Beta Tri, 4 Trianguli, HR 622, HD 13161, BD+34°381, FK5 75, HIP 10064, SAO 55306.[10]
Database references
SIMBADdata

Beta Trianguli (Beta Tri, β Trianguli, β Tri) is the Bayer designation for a binary star[11] system in the constellation Triangulum, located about 127 light years from Earth.[1] Although the apparent magnitude is only 3.0,[2] it is the brightest star in the constellation Triangulum.[12]

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 less than 5 AU.[13] 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.[7] It is among the least variable of the stars that were observed by the Hipparcos spacecraft, with a magnitude varying by only 0.0005.[14]

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.[7]

Naming[edit]

References[edit]

  1. ^ a b c d e f 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.
  2. ^ a b c d 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. ^ a b c 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.
  4. ^ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W
  5. ^ 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.
  6. ^ a b Pourbaix, D.; et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics, 424: 727–732, arXiv:astro-ph/0406573, Bibcode:2009yCat....102020P, doi:10.1051/0004-6361:20041213.
  7. ^ a b c d 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.
  8. ^ 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
  9. ^ Booth, M.; Kennedy, G.; Sibthorpe, B.; Matthews, B. C.; Wyatt, M. C.; Duchene, G.; Kavelaars, J. J.; Rodriguez, D.; Greaves, J. S.; Koning, A.; Vican, L.; Rieke, G. H.; Su, K. Y. L.; Moro-Martin, A.; Kalas, P. (2012). "Resolved debris discs around a stars in the Herschel DEBRIS survey". Monthly Notices of the Royal Astronomical Society. 428 (2): 1263. arXiv:1210.0547. Bibcode:2013MNRAS.428.1263B. doi:10.1093/mnras/sts117.
  10. ^ "bet Tri -- Spectroscopic binary", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-12
  11. ^ 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
  12. ^ a b Garfinkle, Robert A. (1997), Star-Hopping: Your Visa to Viewing the Universe, Cambridge University Press, p. 238, ISBN 0-521-59889-3
  13. ^ a b 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. Protostars and Planets V. p. 8613. Bibcode:2005prpl.conf.8613S.
  14. ^ Adelman, S. J. (February 2001), "Research Note Hipparcos photometry: The least variable stars", Astronomy and Astrophysics, 367: 297–298, Bibcode:2001A&A...367..297A, doi:10.1051/0004-6361:20000567
  15. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日