Astronomy:Epsilon Trianguli
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[1] mas |
| 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 |
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]
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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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 Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, doi:10.1086/110819, Bibcode: 1969AJ.....74..375C
- ↑ 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, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 6.2 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode: 2012A&A...537A.120Z.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Rhee, Joseph H. et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal 660 (2): 1556–1571, doi:10.1086/509912, Bibcode: 2007ApJ...660.1556R
- ↑ 8.0 8.1 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, doi:10.1051/0004-6361:20053222, Bibcode: 2005A&A...442..563M
- ↑ 9.0 9.1 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, doi:10.1051/0004-6361:20065224, Bibcode: 2007A&A...463..671R
- ↑ "eps Tri -- Variable Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=epsilon+trianguli, 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ 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
- ↑ 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, doi:10.1086/368241, Bibcode: 2003AJ....125.1980K
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