Astronomy:Delta2 Telescopii

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Short description: Star in the constellation Telescopium


Delta2 Telescopii
Observation data
Equinox J2000.0]] (ICRS)
Constellation Telescopium
Right ascension  18h 32m 01.94437s[1]
Declination −45° 45′ 26.5636″[1]
Apparent magnitude (V) 5.05[2]
Characteristics
Spectral type B3 IV/V[3] or B3 III[4]
U−B color index −0.52[2]
B−V color index −0.12[2]
Astrometry
Proper motion (μ) RA: +0.16[1] mas/yr
Dec.: −10.23[1] mas/yr
Parallax (π)2.73 ± 0.26[1] mas
Distance1,200 ± 100 ly
(370 ± 30 pc)
Absolute magnitude (MV)−1.46[5]
Orbit[6]
Period (P)21.7056 d
Eccentricity (e)0.22
Periastron epoch (T)2,435,216.669 JD
Argument of periastron (ω)
(secondary)
12.7°
Semi-amplitude (K1)
(primary)
34.9 km/s
Details
Mass7.6±0.1[7] M
Luminosity (bolometric)5,129[8] L
Temperature17,100[8] K
Rotational velocity (v sin i)0[9] or 45[4] km/s
Age39.8±7.6[7] Myr
Other designations
δ2 Tel, CD−45° 12556, HD 170523, HIP 90853, HR 6938, SAO 229095[10]
Database references
SIMBADdata

Delta2 Telescopii is a blue-white-hued binary star[6] system in the southern constellation of Telescopium. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.05.[2] The distance to this system, as determined with an annual parallax shift of 2.73 mas,[1] is roughly 1,200 light-years. At that distance, the visual magnitude of the star is diminished by an extinction of 0.36 due to interstellar dust.[5] The pair have an orbital period of 21.7 days and an eccentricity of 0.22.[6] For the merged stellar classification, Houk (1978) gives B3 IV/V,[3] while Levato (1975) lists a more evolved class of B3 III.[4] It appears to be a relatively young system, barely 40 million years old.[7]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Fernie, J. D. (May 1983), "New UBVRI photometry for 900 supergiants", Astrophysical Journal Supplement Series 52: 7–22, doi:10.1086/190856, Bibcode1983ApJS...52....7F. 
  3. 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1978mcts.book.....H. 
  4. 4.0 4.1 4.2 Levato, H. (1975), "Rotational velocities and spectral types for a sample of binary systems", Astronomy and Astrophysics 19: 91, Bibcode1975A&AS...19...91L. 
  5. 5.0 5.1 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode2012AstL...38..694G. 
  6. 6.0 6.1 6.2 Pourbaix, D. et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics 424: 727–732, doi:10.1051/0004-6361:20041213, Bibcode2004A&A...424..727P. 
  7. 7.0 7.1 7.2 Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T. 
  8. 8.0 8.1 Hohle, M. M. et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten 331 (4): 349, doi:10.1002/asna.200911355, Bibcode2010AN....331..349H. 
  9. Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory (University of Kyoto), Bibcode1970crvs.book.....U. 
  10. "del02 Tel". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=del02+Tel.