Delta1 Telescopii
Delta1 Telescopii is a blue-white hued binary star[5] system in the southern constellation of Telescopium. It is faintly visible to the naked eye, having an apparent visual magnitude of 4.94.[2] Based upon an annual parallax shift of 4.61 mas as seen from Earth,[1] this system is roughly 710 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.29 due to interstellar dust.[4]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 18h 31m 45.43288s[1] |
| Declination | −45° 54′ 53.3166″[1] |
| Apparent magnitude (V) | 4.94[2] |
| Characteristics | |
| Spectral type | B6 IV[3] |
| U−B color index | −0.438[2] |
| B−V color index | −0.121[2] |
| Astrometry | |
| Proper motion (μ) | RA: −3.75[1] mas/yr Dec.: −27.43[1] mas/yr |
| Parallax (π) | 4.61 ± 0.19[1] mas |
| Distance | 710 ± 30 ly (217 ± 9 pc) |
| Absolute magnitude (MV) | −0.74[4] |
| Orbit[5] | |
| Period (P) | 18.8456 d |
| Eccentricity (e) | 0.51 |
| Periastron epoch (T) | 2435003.693 JD |
| Argument of periastron (ω) (secondary) | 78° |
| Semi-amplitude (K1) (primary) | 65.0 km/s |
| Details | |
| δ1 Tel A | |
| Mass | 4.52±0.06[3] M☉ |
| Radius | 4.7[6] R☉ |
| Luminosity | 899[3] L☉ |
| Temperature | 12,417[3] K |
| Rotational velocity (v sin i) | 11[3] km/s |
| Age | 178[4] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This system is a single-lined spectroscopic binary with an orbital period of 18.8 days and an eccentricity of 0.51.[5] The estimated size of the semimajor axis has a minimum of 14.5×106 km, with the uncertainty due to lack of a value for the orbital inclination.[8] The primary, component A, has a stellar classification of B6 IV,[3] suggesting it is an evolving B-type subgiant star. Delta1 Telescopii has an estimated 4.5[3] times the mass of the Sun and about 4.7[6] times the Sun's radius. It is radiating 899[3] times the solar luminosity from its photosphere at an effective temperature of 12,417 K.[3]
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.
- Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
- Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.
- 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.
- Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (3rd ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
- "del01 Tel -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-06-07.
- Buscombe, W.; Kennedy, P. M. (August 1962), "Two B-Type Spectroscopic Binaries", Publications of the Astronomical Society of the Pacific, 74 (439): 323, Bibcode:1962PASP...74..323B, doi:10.1086/127818.