7 Trianguli
Location of 7 Trianguli (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
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 mas[1]
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
7 Trianguli, AG+33° 210, BD+32° 409, GC 2710, HD 13869, HIP 10559, HR 655, SAO 55397
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. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
  3. ^ a b 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. Bibcode:1969AJ.....74..375C. doi:10.1086/110819. ISSN 0004-6256.
  4. ^ a b Eggen, O. J. (1962). "Space-velocity vectors for 3483 stars with proper motion and radial velocity". Royal Greenwich Observatory Bulletins. 51: 79. Bibcode:1962RGOB...51...79E.
  5. ^ a b 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. Bibcode:1993Ap&SS.203...53H. doi:10.1007/BF00659414. ISSN 0004-640X.
  6. ^ a b Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication: 0. Bibcode:1953GCRV..C......0W.
  7. ^ 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.
  8. ^ a b c d e f g 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. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. ISSN 0004-637X.
  9. ^ a b c d Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
  10. ^ a b Glebocki, R.; Gnacinski, P.; Stawikowski, A. (December 2000). "Catalog of Projected Rotational Velocities". Acta Astronomica. 50: 509–515. Bibcode:2000AcA....50..509G. ISSN 0001-5237.
  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. ^ 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. Bibcode:1980A&AS...40..207C.
  13. ^ Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
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