Epsilon Trianguli

ε Trianguli
Location of ε Trianguli (circled)
Observation data
Epoch J2000.0      Equinox ICRS
Constellation Triangulum
Right ascension 02h 02m 57.95579s
Declination +33° 17′ 02.8813″
Apparent magnitude (V) +5.50
Characteristics
Evolutionary stage main sequence
Spectral type A2 V
U−B color index +0.06
B−V color index +0.03
Astrometry
Radial velocity (Rv)3.3 km/s
Proper motion (μ) RA: −15.97 mas/yr
Dec.: −7.22 mas/yr
Parallax (π)8.33±0.34 mas
Distance390 ± 20 ly
(120 ± 5 pc)
Absolute magnitude (MV)+0.11
Details
Mass2.75±0.05 M☉
Radius3.28 R☉
Luminosity93 L☉
Surface gravity (log g)3.76 cgs
Temperature10,000 K
Rotational velocity (v sin i)107 km/s
Age600 Myr
Other designations
ε Tri, 3 Tri, BD+32°369, HD 12471, HIP 9570, HR 599, SAO 55218
Database references
SIMBADdata

Epsilon Trianguli, Latinized from ε Trianguli, is a binary star system in the northern constellation of Triangulum. Based upon measurement of its trigonometric parallax, it is approximately 390 light years from Earth.

The primary component is an A-type main sequence star with a stellar classification of A2 V, an apparent magnitude of +5.50 and an estimated age of 600 million years. It has 2.75 times the mass of the Sun and is spinning with a projected rotational velocity of 107 km/s. The radius of this star is more than three times the radius of the Sun, and the photosphere has an effective temperature of about 10,000. The secondary component has an apparent magnitude of 11.4 and is separated from the primary by an angle of 3.9 arcseconds.

An excess emission of infrared radiation suggests the presence of a dusty disk in orbit about the primary. This disk has a mean radius of 105 AU, or 105 times the separation of the Earth from the Sun, and is radiating at a temperature of 85 K.

Epsilon Triangulum is a probable member of the Ursa Major Moving Group of stars that share a common motion through space. The space velocity components of Epsilon Trianguli are [U, V, W] = [+11.8, +11.4, –3.8] km/s.

References

  1. 1 2 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. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 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.
  3. 1 2 3 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
  4. 1 2 3 4 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
  5. 1 2 Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819
  6. ↑ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W
  7. 1 2 3 4 5 6 Rhee, Joseph H.; et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal, 660 (2): 1556–1571, arXiv:astro-ph/0609555, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912, S2CID 11879505
  8. 1 2 Monier, R. (November 2005), "Abundances of a sample of A and F-type dwarf members of the Ursa Major Group", Astronomy and Astrophysics, 442 (2): 563–566, Bibcode:2005A&A...442..563M, doi:10.1051/0004-6361:20053222
  9. 1 2 Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298
  10. ↑ "eps Tri -- Variable Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-13
  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, S2CID 14878976.
  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
  13. ↑ King, Jeremy R.; et al. (April 2003), "Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group", The Astronomical Journal, 125 (4): 1980–2017, Bibcode:2003AJ....125.1980K, doi:10.1086/368241