Beta Trianguli

Not to be confused with Beta Trianguli Australis.
β Trianguli
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] (3.44 + 4.19)[3]
Characteristics
Spectral type A8III + A3III[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 mas[1]
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[3]
A
Mass2.6±0.3 M☉
Radius4.38 R☉
Luminosity60 L☉
Surface gravity (log g)3.70[7] cgs
Temperature7,683 K
Rotational velocity (v sin i)70[8] km/s
Age0.40 Gyr
B
Mass2.25±0.05 M☉
Radius2.44 R☉
Luminosity32 L☉
Temperature8,759 K
Other designations
β Trianguli, β Tri, Beta Tri, 4 Trianguli, HR 622, HD 13161, BD+34°381, FK5 75, HIP 10064, SAO 55306.[9]
Database references
SIMBADdata

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]

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.[12] 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.[13] 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.[12] It is thought to extend from 50 to 400 AU away from the stars.[13]

  1. ^ a b c d e f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Piccotti was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcrv1953 was invoked but never defined (see the help page).
  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, S2CID 119257644.
  6. ^ a b 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.
  7. ^ 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.
  8. ^ Cite error: The named reference aaa393_897 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference garfinckle1997 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference pap5 was invoked but never defined (see the help page).
  13. ^ a b 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.
  14. ^ Cite error: The named reference aaa367_297 was invoked but never defined (see the help page).