V Hydrae
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 10h 51m 37.25661s[1] |
| Declination | −21° 15′ 00.3245″[1] |
| Apparent magnitude (V) | 6.0 - 12.3[2] |
| Characteristics | |
| Spectral type | C6,3e-C7,5e(N6e)[3] |
| Variable type | SRa[3] |
| Astrometry | |
| Radial velocity (Rv) | −14.80[4] km/s |
| Proper motion (μ) | RA: −11.02 ± 1.14[1] mas/yr Dec.: 2.29 ± 1.16[1] mas/yr |
| Parallax (π) | 1.44 ± 1.41 mas[1] |
| Distance | approx. 2,000 ly (approx. 700 pc) |
| Orbit[5] | |
| Period (P) | 8.5 yr |
| Eccentricity (e) | ≥0.6 |
| Details | |
| A | |
| Mass | 1.0[6] M☉ |
| Radius | 430[5] R☉ |
| Luminosity | 7,850[6] L☉ |
| Surface gravity (log g) | −0.5[6] cgs |
| Temperature | 2,650[6] K |
| Rotational velocity (v sin i) | 11 - 14[6] km/s |
| B | |
| Mass | <1[5] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
V Hydrae (V Hya) is a variable star in the constellation Hydra. It is considered by astronomers to be a carbon star. With a B-V colour index of +5.5 it is one of the reddest stars visible.[7] It has a period of approximately 18 years and a sub-period of approximately 530 days.
References
- ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ^ Watson, Christopher (4 January 2010). "V Hydrae". The International Variable Star Index. American Association of Variable Star Observers. Retrieved 2016-10-12.
- ^ 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. Bibcode:2009yCat....102025S.
- ^ . Bibcode:2006AstL...32..759G.
{{cite journal}}: Cite journal requires|journal=(help); Missing or empty|title=(help) - ^ a b c . arXiv:1605.06728. Bibcode:2016ApJ...827...92S.
{{cite journal}}: Cite journal requires|journal=(help); Missing or empty|title=(help) - ^ a b c d e . arXiv:1207.3767. Bibcode:2012A&A...545A..56Z.
{{cite journal}}: Cite journal requires|journal=(help); Missing or empty|title=(help) - ^ "Redder than Red: V Hydrae". Astro Guyz.
- "V* V Hya - Semi-regular pulsating Star". SIMBAD Astronomical Database.