6 Sagittarii is a massive, orange-hued star in the southern zodiac constellation of Sagittarius. With an apparent visual magnitude of 6.27,[2] it is just below the nominal brightness limit for visibility with the typical naked eye under ideal viewing conditions. The distance can be estimated from the annual parallax shift of 1.24±0.44 mas[1] as roughly 2,600 light years away. It is moving closer to the Sun with a heliocentric radial velocity of −22 km/s.[2] 6 Sagittarii has a peculiar velocity of 31.8+9.9
−14.1 km/s, which may indicate it is a runaway star.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 01m 23.12190s[1] |
| Declination | −17° 09′ 24.7302″[1] |
| Apparent magnitude (V) | 6.27[2] |
| Characteristics | |
| Spectral type | K2 III[3] |
| B−V color index | 1.763±0.010[4] |
| Astrometry | |
| Radial velocity (Rv) | −22.0±4.3[2] km/s |
| Proper motion (μ) | RA: −0.86[1] mas/yr Dec.: −7.15[1] mas/yr |
| Parallax (π) | 1.24 ± 0.44 mas[1] |
| Distance | approx. 2,600 ly (approx. 800 pc) |
| Details | |
| Mass | 10.6±1.9[5] M☉ |
| Luminosity | 6,816.79[6] L☉ |
| Temperature | 3,778[6] K |
| Age | 25.1±3.8[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved giant star with a stellar classification of K2 III.[3] It is only 25[5] million years old and has around ten times the mass of the Sun.[5] The star is radiating about 6,817 times the Sun's luminosity from its photosphere at an effective temperature of 3,778 K.[6] It appears to be a source of extended infrared excess, but this emission may be due to intervening cirrus.[8]
References
edit- ^ 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.
- ^ a b c d Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ^ 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.
- ^ a b c d e Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (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.
- ^ a b c McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–357, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
- ^ "6 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-14.
- ^ Plets, H.; et al. (July 1997), "Giants with infrared excess", Astronomy and Astrophysics, 323: 513–523, Bibcode:1997A&A...323..513P.