Epsilon Trianguli
Epsilon Trianguli, Latinized from ε Trianguli, is a binary star[11] system in the northern constellation of Triangulum. Based upon measurement of its trigonometric parallax, it is approximately 390 light years from Earth.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 02h 02m 57.95579s[1] |
| Declination | +33° 17′ 02.8813″[1] |
| Apparent magnitude (V) | +5.50[2] |
| Characteristics | |
| Spectral type | A2 V[3] |
| U−B color index | +0.06[2] |
| B−V color index | +0.03[2] |
| Astrometry | |
| Radial velocity (Rv) | 3.3[4] km/s |
| Proper motion (μ) | RA: –15.97[1] mas/yr Dec.: –7.22[1] mas/yr |
| Parallax (π) | 8.33 ± 0.34 mas[1] |
| Distance | 390 ± 20 ly (120 ± 5 pc) |
| Absolute magnitude (MV) | +0.11[5] |
| Details | |
| Mass | 2.75±0.05[6] M☉ |
| Radius | 3.28[7] R☉ |
| Luminosity | 93[6] L☉ |
| Surface gravity (log g) | 3.76[8] cgs |
| Temperature | 10,000[7] K |
| Rotational velocity (v sin i) | 107[9] km/s |
| Age | 600[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary component is an A-type main sequence star with a stellar classification of A2 V,[3] an apparent magnitude of +5.50 and an estimated age of 600 million years.[7] It has 2.75[6] times the mass of the Sun and is spinning with a projected rotational velocity of 107 km/s.[9] 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.[7] The secondary component has an apparent magnitude of 11.4 and is separated from the primary by an angle of 3.9 arcseconds.[12]
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.[7]
This star system is a probable member of the Ursa Major Moving Group of stars that share a common motion through space.[8] The space velocity components of Epsilon Trianguli are [U, V, W] = [+11.8, +11.4, –3.8] km/s.[13]
References Edit
- ^ 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. S2CID 18759600.
- ^ a b c 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
- ^ a b 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
- ^ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication, 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.
- ^ a b c 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.
- ^ a b c d e f 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
- ^ a b 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
- ^ a b 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
- ^ "eps Tri -- Variable Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-13
- ^ 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.
- ^ 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
- ^ 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