Beta Hydrae
From Infogalactic: the planetary knowledge core
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) |
|
|---|---|
| Constellation | Hydra |
| A | |
| Right ascension | 11h 52m 54.521s |
| Declination | −33° 54′ 29.25″[1] |
| Apparent magnitude (V) | 4.67;[2] 4.276(combined)[3] |
| B | |
| Right ascension | 11h 52m 54.550s |
| Declination | −33° 54′ 28.73″[4] |
| Apparent magnitude (V) | 5.47[2] |
| Characteristics | |
| U−B color index | −0.33[5] |
| B−V color index | −0.10[5] |
| R−I color index | −0.08[5] |
| A | |
| Spectral type | B9IIIsp...[3] |
| Variable type | ACV[6] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −1 ± 5[3] km/s |
| Proper motion (μ) | RA: −58.02 [1] mas/yr Dec.: 2.40[1] mas/yr |
| Parallax (π) | 8.93 ± 0.88[3] mas |
| Distance | 370 ± 40 ly (110 ± 10 pc) |
| Absolute magnitude (MV) | −1.0[7] |
| B | |
| Proper motion (μ) | RA: −52.70[4] mas/yr Dec.: −8.94[4] mas/yr |
| Details | |
| A | |
| Mass | 3.36 ± 0.15[8] M☉ |
| Radius | 4.0 ± 0.6[8] R☉ |
| Luminosity (bolometric) | 210[9] L☉ |
| Temperature | 11,100[8] K |
| Age | 2.2 × 108 [9] years |
| B | |
| Mass | ~3[9] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Beta Hydrae (Beta Hya, β Hydrae, β Hya) is a double star in the constellation of Hydra.[3] Its overall apparent visual magnitude varies by 0.04 magnitudes with a period of 2.344 days, and is approximately 4.27 at maximum brightness.[10] The brighter star in the double is a giant Bp star which has been classified as an α2 Canum Venaticorum variable.[3][6]
Beta Hydrae was a latter designation of 28 Crateris.[11]
References
- ↑ 1.0 1.1 1.2 HIP 57936, record for component 1, Hipparcos catalogue; CDS ID I/239.
- ↑ 2.0 2.1 2.2 Entry 11529-3354, The Washington Double Star Catalog, United States Naval Observatory. Accessed on line September 23, 2008.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 V* alf Dor -- Variable Star, database entry, SIMBAD. Accessed on line September 3, 2008.
- ↑ 4.0 4.1 4.2 HIP 57936, record for component 2, Hipparcos catalogue; CDS ID I/239.
- ↑ 5.0 5.1 5.2 HR 4552, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 23, 2008.
- ↑ 6.0 6.1 Notes, Entry 11529-3354, The Washington Double Star Catalog, United States Naval Observatory. Accessed on line September 23, 2008.
- ↑ From apparent magnitude and parallax.
- ↑ 8.0 8.1 8.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 9.0 9.1 9.2 Beta Hydrae, Stars, Jim Kaler. Accessed on line September 23, 2008.
- ↑ bet Hya, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line September 23, 2008.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
