Delta2 Telescopii
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]
| 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[1] mas |
| Distance | 1,200 ± 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) | 2435216.669 JD |
| Argument of periastron (ω) (secondary) | 12.7° |
| Semi-amplitude (K1) (primary) | 34.9 km/s |
| Details | |
| Mass | 7.6±0.1[7] M☉ |
| Luminosity (bolometric) | 5,129[8] L☉ |
| Temperature | 17,100[8] K |
| Rotational velocity (v sin i) | 0[9] or 45[4] km/s |
| Age | 39.8±7.6[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
References
- 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.
- 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.
- Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- Levato, H. (1975), "Rotational velocities and spectral types for a sample of binary systems", Astronomy and Astrophysics, 19: 91, Bibcode:1975A&AS...19...91L.
- 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.
- 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.
- 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.
- 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.
- 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.
- "del02 Tel". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-07.
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