Astronomy:7 Trianguli

From HandWiki
Short description: Star in the constellation Triangulum
7 Trianguli
Triangulum constellation map.svg
Red circle.svg
Location of 7 Trianguli (circled)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Triangulum
Right ascension  02h 15m 56.2876s[1]
Declination +33° 21′ 32.032″[1]
Apparent magnitude (V) 5.25±0.01[2]
Characteristics
Spectral type A0 V[3] or B9.5 V[4]
U−B color index −0.03[5]
B−V color index −0.01[5]
Astrometry
Radial velocity (Rv)−1.3±2[6] km/s
Proper motion (μ) RA: −15.234[1] mas/yr
Dec.: −32.711[1] mas/yr
Parallax (π)9.0683 ± 0.137[1] mas
Distance360 ± 5 ly
(110 ± 2 pc)
Absolute magnitude (MV)0.58[7]
Details
Mass2.77[8] M
Radius3.24±0.11[9] R
Luminosity89.1+10.5
−8.1
[9] L
Surface gravity (log g)4.02±0.14[8] cgs
Temperature10685±363[8] K
Rotational velocity (v sin i)130[10] km/s
Age283[8] Myr
Other designations
Database references
SIMBADdata

7 Trianguli is a solitary[11] star located in the northern constellation Triangulum. It has an apparent magnitude of 5.25,[2] making it faintly visible to the naked eye under ideal conditions. The star is situated at distance of 360 light years[1] but is approaching with a heliocentric radial velocity of −1.3 km/s,[6] which is poorly constrained.

7 Trianguli has a stellar classification of A0 V[3] or B9.5 V,[4] depending on the study. At present it has 2.77 times the mass of the Sun[8] and 3.24 times the radius of the Sun.[9] It shines at 89.1 times the luminosity of the Sun[9] from its photosphere at an effective temperature of 10,685 K,[8] giving it a blueish white glow. 7 Trianguli is a young star, with an age of 283 million years[8] and spins rapidly with a projected rotational velocity of 130 km/s.[10] It has been classified as having a peculiar spectrum,[12] but it is considered doubtful that it is actually a chemically peculiar star.[13]

Together with δ Trianguli and γ Trianguli, it forms an optical (line-of-sight) triple.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  2. 2.0 2.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Cowley, A.; Cowley, C.; Jaschek, M.; Jaschek, C. (April 1969). "A study of the bright stars. I. A catalogue of spectral classifications.". The Astronomical Journal 74: 375. doi:10.1086/110819. ISSN 0004-6256. Bibcode1969AJ.....74..375C. 
  4. 4.0 4.1 Eggen, O. J. (1962). "Space-velocity vectors for 3483 stars with proper motion and radial velocity.". Royal Greenwich Observatory Bulletins 51: 79. Bibcode1962RGOB...51...79E. 
  5. 5.0 5.1 Hamdy, M. A.; Abo Elazm, M. S.; Saad, S. M. (1993). "A catalogue of spectral classification and photometric data of B-type stars". Astrophysics and Space Science 203 (1): 53–107. doi:10.1007/BF00659414. ISSN 0004-640X. Bibcode1993Ap&SS.203...53H. 
  6. 6.0 6.1 Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities.". Carnegie Institute Washington D.C. Publication: 0. Bibcode1953GCRV..C......0W. 
  7. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  8. 8.0 8.1 8.2 8.3 8.4 8.5 8.6 David, Trevor J.; Hillenbrand, Lynne A. (12 May 2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal 804 (2): 146. doi:10.1088/0004-637X/804/2/146. ISSN 0004-637X. Bibcode2015ApJ...804..146D. 
  9. 9.0 9.1 9.2 9.3 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Bibcode2019AJ....158..138S. 
  10. 10.0 10.1 Glebocki, R.; Gnacinski, P.; Stawikowski, A. (December 2000). "Catalog of Projected Rotational Velocities". Acta Astronomica 50: 509–515. ISSN 0001-5237. Bibcode2000AcA....50..509G. 
  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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E 
  12. Cucchiaro, A.; Jaschek, M.; Jaschek, C.; Macau-Hercot, D. (1980). "Spectral classification from the ultraviolet line features of S2/68 spectra". Astronomy and Astrophysics Supplement Series 40: 207. Bibcode1980A&AS...40..207C. 
  13. Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics 498 (3): 961–966. doi:10.1051/0004-6361/200810788. Bibcode2009A&A...498..961R.