KY Cygni
|
Star KY Cygni |
|||||||
|---|---|---|---|---|---|---|---|
|
|||||||
| Comparison of some stars with a very large radius | |||||||
| AladinLite | |||||||
|
Observation dates equinox : J2000.0 , epoch : J2000.0 |
|||||||
| Constellation | swan | ||||||
| Right ascension | 20 h 25 m 58.04 s | ||||||
| declination | + 38 ° 21 ′ 7.7 ″ | ||||||
| Apparent brightness | 13.50 likes | ||||||
| Typing | |||||||
|
rel. Brightness (G-band) |
(7.07 ± 0.01) mag | ||||||
| rel. Brightness (J-band) |
(2.64) mag | ||||||
| Spectral class | M3.5 Ia | ||||||
| Variable star type | LC | ||||||
| Astrometry | |||||||
| parallax | (0.92 ± 0.09) mas | ||||||
| distance | 3,500 ly 1,000 pc |
||||||
| Visual absolute brightness M vis | −8.18 mag | ||||||
| Proper movement | |||||||
| Rec. Share: | (−3.57 ± 0.18) mas / a | ||||||
| Dec. portion: | (−6.28 ± 0.16) mas / a | ||||||
| Physical Properties | |||||||
| radius | 1420 R ☉ | ||||||
| Effective temperature | 3500 K | ||||||
|
Other names and catalog entries |
|||||||
|
|||||||
KY Cygni is a red supergiant of the spectral class M3.5 Ia in the constellation Swan . It is one of the largest known stars with about 1500 times the solar diameter . It is also one of the brightest stars . Based on previous measurements, the distance to KY Cygni has been estimated to be about 5000 light years . Data from Gaia DR2 indicate a closer distance of about 3500 light years.
The spectrum of the star is extremely shifted into the red area. Therefore it has an apparent brightness of only 13.5 magnitudes in the visual area ( V-band ) . Its G-band magnitude is already magnitude 7 and in the infrared J-band it has a high brightness of magnitude 2.6.
The name part "KY" follows the rules for naming variable stars and says that KY Cygni is the 258th variable star discovered in the constellation Swan .
Web links
Individual evidence
- ↑ a b c d e f KY Cyg. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on September 22, 2019 .
- ↑ a b KY Cyg. In: VSX. AAVSO, accessed January 19, 2019 .
- ↑ a b c Emily M. Levesque, Philip Massey, KAG Olsen, Bertrand Plez, Eric Josselin, Andre Maeder, Georges Meynet: The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought . In: The Astrophysical Journal . 628, No. 2, 2005, pp. 973-985. arxiv : astro-ph / 0504337 . bibcode : 2005ApJ ... 628..973L . doi : 10.1086 / 430901 .