23 Cygni is a single,[2] blue-white hued star in the northern constellation Cygnus. It is a faint star, visible to the naked eye, with an apparent visual magnitude of 5.14.[2] The distance to this star, as estimated from its annual parallax shift of 5.9 mas,[1] is about 550 light years. It is moving closer to the Earth with a heliocentric radial velocity of −32 km/s,[4] and is expected to come as near as 166 light-years in around 5.6 million years.[2] At that distance, the current star would be of magnitude 2.24.[8]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 53m 17.37873s[1] |
| Declination | +57° 31′ 24.4810″[1] |
| Apparent magnitude (V) | 5.14[2] |
| Characteristics | |
| Spectral type | B5 V[3] |
| U−B color index | +0.76[2] |
| B−V color index | −0.13[2] |
| Astrometry | |
| Radial velocity (Rv) | −31.6±1.6[4] km/s |
| Proper motion (μ) | RA: +5.768[1] mas/yr Dec.: +11.483[1] mas/yr |
| Parallax (π) | 5.9155 ± 0.1728 mas[1] |
| Distance | 550 ± 20 ly (169 ± 5 pc) |
| Absolute magnitude (MV) | −1.30[5] |
| Details[2] | |
| Mass | 4.7+0.64 −0.53[6] M☉ |
| Radius | 4.30±0.45 R☉ |
| Luminosity | 611.53[5] L☉ |
| Surface gravity (log g) | 3.82±0.08 cgs |
| Temperature | 14,893±214 K |
| Metallicity [Fe/H] | −0.17±0.16 dex |
| Rotational velocity (v sin i) | 145 km/s |
| Age | 26+32 −19[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary B-type main-sequence star of spectral type B5V, a star that is generating energy through hydrogen fusion at its core. It is roughly 26[2] million years old with 4.7[6] times the mass of the Sun and 4.3 times the Sun's radius.[2] The star has a high rate of spin, having a projected rotational velocity of 145 km/s.[2] It is radiating 612[5] times the Sun's luminosity from its photosphere at an effective temperature of 14,893 K.[2]
References
edit- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g h i j k Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal, 129 (3): 1642–1662, arXiv:astro-ph/0412542, Bibcode:2005AJ....129.1642F, doi:10.1086/427855, S2CID 119512018.
- ^ Hill, P. W.; Lynas-Gray, A. E. (September 1977), "UBV photometry and MK spectral classification of northern early-type stars at intermediate galactic latitudes.", Monthly Notices of the Royal Astronomical Society, 180 (4): 691–702, Bibcode:1977MNRAS.180..691H, doi:10.1093/mnras/180.4.691.
- ^ a b 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 c 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 Gullikson, Kevin; et al. (August 2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", The Astronomical Journal, 152 (2): 13, arXiv:1604.06456, Bibcode:2016AJ....152...40G, doi:10.3847/0004-6256/152/2/40, S2CID 119179065, 40.
- ^ "23 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-09.
- ^ At a distance (D) of 50.99 and an absolute magnitude (M) of −1.30, ignoring extinction (A), the apparent magnitude (m) would be:
- m = M + A + 5·log D + 5 ≈ −1.30 + 5·log 50.99 − 5 = 2.24