KU Hydrae
KU Hydrae is a binary star in the constellation Hydra. The primary star is an Alpha2 Canum Venaticorum variable with its apparent magnitude varying from 0.05 magnitudes over a period of 33.97 days.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra[1] |
| Right ascension | 09h 22m 50.856s[2] |
| Declination | −09° 50′ 19.66″[2] |
| Apparent magnitude (V) | 6.75[3] |
| Characteristics | |
| Spectral type | Ap EuCrSr[4] |
| U−B color index | +0.11[5] |
| B−V color index | +0.22[5] |
| Variable type | α2 CVn |
| Astrometry | |
| Radial velocity (Rv) | 19.6 ± 5.0 km/s |
| Proper motion (μ) | RA: −27.94 ± 0.61[2] mas/yr Dec.: −13.01 ± 0.36[2] mas/yr |
| Parallax (π) | 6.92 ± 0.61[2] mas |
| Distance | 470 ± 40 ly (140 ± 10 pc) |
| Orbit[6] | |
| Companion | KU Hya B |
| Period (P) | 53.199 ± 0.193 yr |
| Semi-major axis (a) | 0.165 ± 0.011″ |
| Eccentricity (e) | 0.038 ± 0.037 |
| Inclination (i) | 67.1 ± 4.1° |
| Longitude of the node (Ω) | 23.7 ± 3.6° |
| Periastron epoch (T) | 1957.346 ± 0.572 |
| Details[6] | |
| KU Hya A | |
| Mass | 2.07 M☉ |
| KU Hya B | |
| Mass | 2.05 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
This star was discovered to be a visual binary star by Robert Grant Aitken in 1906 and was given the double star designation A 1342.[7] Additional measurements of the position angle and angular separation showed a rapid orbital motion.[8]
References
- Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
- van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.Vizier catalog entry
- Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
- "V* KU Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2014-09-01.
- Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J.
- Rica Romero, F. M. (2010). "Orbital elements for eight binaries. Study of the nature of wide components. I" (PDF). Revista Mexicana de Astronomía y Astrofísica. 46: 263–277. Bibcode:2010RMxAA..46..263R.
- Aitken, Robert Grant (1907). "Two hundred and fifty new double stars: tenth list". Lick Observatory Bulletin. 4 (109): 101–106. Bibcode:1907LicOB...4..101A. doi:10.5479/ADS/bib/1907LicOB.4.101A.
- Aitken, Robert Grant (1929). "Measures of 296 A double stars". Lick Observatory Bulletin. 14 (413): 62–87. Bibcode:1929LicOB..14...62A. doi:10.5479/ADS/bib/1929LicOB.14.62A.
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