Gamma Trianguli
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Triangulum |
Right ascension | 02h 17m 18.86703s[1] |
Declination | +33° 50′ 49.8950″[1] |
Apparent magnitude (V) | +4.01[2] |
Characteristics | |
Spectral type | A1Vnn[3] |
U−B color index | +0.02[2] |
B−V color index | +0.02[2] |
Astrometry | |
Radial velocity (Rv) | +9.9[4] km/s |
Proper motion ( | RA: 44.64[1] mas/yr Dec.: –52.57[1] mas/yr |
Parallax ( | 29.04 ± 0.25 mas[1] |
Distance | 112.3 ± 1.0 ly (34.4 ± 0.3 pc) |
Absolute magnitude (MV) | +1.35[5] |
Details | |
Mass | 2.7[6] M☉ |
Radius | 1.96[7] R☉ |
Luminosity | 33.0[6] L☉ |
Temperature | 9,440[8] K |
Rotational velocity (v sin i) | 254[9] km/s |
Age | 300[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Gamma Trianguli (Gamma Tri,
Properties
[edit]This star has a stellar classification of A1Vnn,[3] which indicates it is an A-type main sequence star. It has 2.7[6] times the mass of the Sun and nearly double the Sun's radius.[7] Gamma Trianguli is radiating about 33[6] times the luminosity of the Sun from its outer envelope at an effective temperature of 9,440 K,[8] giving the star a white hue.[12] The star is roughly 300 million years old.[6]
Rotation
[edit]It is rotating rapidly, with a projected rotational velocity of 254 km/s along the equator,[9] which causes the star to take the pronounced shape of an oblate spheroid like Altair.[11] Because the inclination of the star's axial tilt is unknown, this means that the azimuthal equatorial velocity is at least this amount and possibly higher.[9] By comparison, the Sun is a slow rotator with an equatorial azimuthal velocity of 2 km/s.[13] The doppler shift from the rapid rotation results in very diffuse absorption lines in the star's spectrum, as indicated by the 'nn' in the classification.[14]
Debris disk
[edit]Orbiting the star is a dusty debris disk with a combined mass of about 2.9 × 10−2 times the mass of the Earth. This disk can be detected because it is being heated to a temperature of about 75 K by Gamma Trianguli and is radiating this as infrared energy. The disk is separated from the host star by an angle of 2.24 arcseconds, corresponding to a physical radius of 80
Naming
[edit]In Chinese,
References
[edit]- ^ a b c d e van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600 Note: see VizieR catalogue I/311.
- ^ 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
- ^ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg, 35, Veröffentlichungen des Astronomisches Rechen-Institut Heidelberg: 1, Bibcode:1999VeARI..35....1W
- ^ 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 d e f Wyatt, M. C.; et al. (July 2007), "Steady State Evolution of Debris Disks around A Stars", The Astrophysical Journal, 663 (1): 365–382, arXiv:astro-ph/0703608, Bibcode:2007ApJ...663..365W, doi:10.1086/518404, S2CID 18883195
- ^ a b c Rhee, Joseph H.; Song, Inseok; Zuckerman, B.; McElwain, Michael (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 Zorec, J.; et al. (July 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (
λ _1, D) parameters into Teff", Astronomy and Astrophysics, 501 (1): 297–320, arXiv:0903.5134, Bibcode:2009A&A...501..297Z, doi:10.1051/0004-6361/200811147, S2CID 14969137 - ^ a b c 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
- ^ "gam Tri -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-11
- ^ a b Kaler, James B., "GAMMA TRI (Gamma Trianguli)", Stars, University of Illinois, retrieved 2011-12-11
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-18, retrieved 2012-01-16
- ^ Stix, Michael (2004), The sun: an introduction, Astronomy and astrophysics library (2nd ed.), Springer, p. 423, ISBN 3-540-20741-4
- ^ Kaler, James B. (2011), Stars and Their Spectra: An Introduction to the Spectral Sequence (2nd ed.), Cambridge University Press, p. 88, ISBN 978-0-521-89954-3
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy)
天文 教育 資 訊網 2006年 7月 10日 Archived 2011-07-16 at the Wayback Machine