Delta2 Telescopii

For other stars with this Bayer designation, see δ Telescopii.
Delta2 Telescopii
Observation data
Epoch J2000.0      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 mas[1]
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. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d Fernie, J. D. (May 1983), "New UBVRI photometry for 900 supergiants", Astrophysical Journal Supplement Series, 52: 7–22, Bibcode:1983ApJS...52....7F, doi:10.1086/190856.
  3. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  4. ^ a b c Levato, H. (1975), "Rotational velocities and spectral types for a sample of binary systems", Astronomy and Astrophysics, 19: 91, Bibcode:1975A&AS...19...91L.
  5. ^ a b Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
  6. ^ a b c Pourbaix, D.; et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics, 424: 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
  7. ^ a b c 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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  8. ^ a b Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
  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, Bibcode:1970crvs.book.....U.
  10. ^ "del02 Tel". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-07.{{cite web}}: CS1 maint: postscript (link)