  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Pronunciation | /ˈdɛnɛb/, /ˈdɛnəb/[1] |
| Right ascension | 20h 41m 25.9s[2] |
| Declination | +45° 16′ 49″[2] |
| Apparent magnitude (V) | 1.25[3] (1.21–1.29[4]) |
| Characteristics | |
| Evolutionary stage | Blue supergiant |
| Spectral type | A2 Ia[5] |
| U−B color index | −0.23[3] |
| B−V color index | +0.09[3] |
| Variable type | Alpha Cygni[4] |
| Astrometry | |
| Radial velocity (Rv) | −4.5[6] km/s |
| Proper motion (μ) | RA: 1.99[2] mas/yr Dec.: 1.95[2] mas/yr |
| Parallax (π) | 2.29 ± 0.32 mas[2] |
| Distance | 2,615±215 ly (802±66[7] pc) |
| Absolute magnitude (MV) | −8.38[7] |
| Details[7] | |
| Mass | 19±4 M☉ |
| Radius | 203±17 R☉ |
| Luminosity | 196,000±32,000 L☉ |
| Surface gravity (log g) | 1.10±0.05 cgs |
| Temperature | 8,525±75 K |
| Metallicity [Fe/H] | −0.25 dex |
| Rotational velocity (v sin i) | 20±2 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Deneb (/ˈdɛnɛb/) is a first-magnitude blue supergiant star in the constellation of Cygnus. Deneb is one of the vertices of the asterism known as the Summer Triangle and the "head" of the Northern Cross. It is the brightest star in Cygnus and the 19th brightest star in the night sky, with an average apparent magnitude of +1.25.
Deneb rivals Rigel, a closer blue supergiant, as the most luminous first-magnitude star. However, its distance, and hence luminosity, is poorly known; its luminosity is somewhere between 55,000 and 196,000 times that of the Sun. Its Bayer designation is α Cygni, which is Latinised to Alpha Cygni, abbreviated to Alpha Cyg or α Cyg. At a distance of 802 parsecs, it is the farthest star from Earth with a magnitude higher than 2.50.
- ^ Merriam-Webster, Inc (1998). Merriam-Webster's Collegiate Dictionary. Merriam-Webster. ISBN 978-0-87779-714-2.
- ^ a b c d e Cite error: The named reference
hipparcoswas invoked but never defined (see the help page). - ^ a b c Ducati, J. R. (2002). "VizieR On-Line Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-Line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: 02025. Bibcode:2009yCat....102025S.
- ^ Garrison, R. F. (1993). "Anchor Points for the MK System of Spectral Classification". Bulletin of the American Astronomical Society. 25: 1319. Bibcode:1993AAS...183.1710G. Archived from the original on 2019-06-25. Retrieved 2012-02-04.
- ^ 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 Schiller, F.; Przybilla, N. (2008). "Quantitative spectroscopy of Deneb". Astronomy & Astrophysics. 479 (3): 849–858. arXiv:0712.0040. Bibcode:2008A&A...479..849S. doi:10.1051/0004-6361:20078590. S2CID 119225384.