BC Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 21m 38.55s |
| Declination | 37° 31′ 58.9″ |
| Apparent magnitude (V) | 9.0 - 10.8[1] |
| Characteristics | |
| Spectral type | M3.5 Ia[2] (M2 - M5[3]) |
| B−V color index | +3.13 - +3.21[3] |
| Variable type | SRc[2] |
| Astrometry | |
| Distance | 1,230[3] pc |
| Absolute magnitude (MV) | −7.71[4] |
| Details[3] | |
| Mass | 19 M☉ |
| Minimum (1900) | |
| Radius | 1,553 R☉ |
| Luminosity | 145,000 L☉ |
| Temperature | 2,858 K |
| Maximum (2000) | |
| Radius | 856 R☉ |
| Luminosity | 112,000 L☉ |
| Temperature | 3,614 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
BC Cygni (BC Cyg / HIP 100404 / BD + 37 3903) is a variable star in the constellation Cygnus, an apparent magnitude +9.97.
Location
It is considered a member of the stellar Cygnus OB1 association, and within it the open cluster Berkeley 87.2 which would place at a distance of 1,500 parsecs (4,890 light-years) of the Solar System; however, according to the measure of the parallax by the satellite Hipparcos (1.20 milliarcseconds).
Stellar Properties
BC Cygni is a red supergiant of spectral type M3.5Ia with an effective temperature 2,858 to 3,614 K, it is one of largest stars and with a radius 1,553 to 856 R☉. If I were in the place of the Sun, the orbits of the planets Jupiter inclusives first five would be included within the star. However, it is surpassed in size by other stars like VY Canis Majoris or VV Cephei, both in the Milky Way galaxy, or WOH G64 in the nearby Large Magellanic Cloud. With a mass of about 19 solar masses, It's estimated that the stellar mass loss, as dust, as the atomic and molecular gas could not be evaluators is 3.2 × 10-9 solar masses per year. This mass is an indication that this star will end up exploding as a supernova.
Billed as a variable star pulsating, BC Cygni brightness varies from magnitude +9.0 and +10.8 with a period of 720 ± 40 days.[1] Between 1,900 and 2,000 appears to have increased its average brightness of 0.5 magnitudes.[3]
References
- 1 2 Kiss, L. L.; Szabó, Gy. M.; Bedding, T. R. (2006). "Variability in red supergiant stars: Pulsations, long secondary periods and convection noise". Monthly Notices of the Royal Astronomical Society. 372 (4): 1721. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x.
- 1 2 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. Bibcode:2009yCat....102025S.
- 1 2 3 4 5 Turner, David G.; Rohanizadegan, Mina; Berdnikov, Leonid N.; Pastukhova, Elena N. (2006). "The Long-Term Behavior of the Semiregular M Supergiant Variable BC Cygni". The Publications of the Astronomical Society of the Pacific. 118 (849): 1533. Bibcode:2006PASP..118.1533T. doi:10.1086/508905.
- ↑ Levesque, Emily M.; Massey, Philip; Olsen, K. A. G.; Plez, Bertrand; Josselin, Eric; Maeder, Andre; Meynet, Georges (2005). "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought". The Astrophysical Journal. 628 (2): 973. Bibcode:2005ApJ...628..973L. doi:10.1086/430901.