t1Hydrae
catalogues and names
| catalogues and names | t1Hya, NSV 18209, 31 Hya, HR 3759, HD 81997, SAO 136895, BD -2 2901, WDS 09291-0246A |
| constellation | Hydra |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 9h 29min 8.9sec | DEC: -2° 46' 8'' | ||
| position (B1900) | RA: 9h 24min 4.3sec | DEC: -2° 19' 55'' | ||
| proper motion (J2000) | RA: 0.13 arcsec/a | DEC: -0.015 arcsec/a | ||
| radial velocity | 10 km/s note: suspected variable radial velocity |
|||
| rotational velocity | 28 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0.072 arcsec | |||
| galactic coordinates | longitude: 236.23° | latitude: 32.86° | ||
magnitude
| visual magnitude | 4.6 (V on UBV Johnson system) |
spectral / color information
| spectral class | F6V |
| B-V-magnitude | 0.46 |
| U-B-magnitude | 0 |
| R-I-magnitude |
double/multiple star system information
| separation | 65.7 arcsec |
| mag difference (of double or brightest multiple) | 3 |
| note | Worley (1978) update of the IDS |
| note (category: double and multiple data): | CPM. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 9h 29min 8.895sec | DEC: -2° 46' 8.77'' | ±0.2 arcsec | source: 52 |
| proper motion (J2000) | RA: 0.0087 arcsec/a | DEC: -0.022 arcsec/a | source: 25 | |
| radial velocity | 10 km/s | source: 25 | ||
| trigonometric parallax | 0.072 arcsec | ±0.007 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 236.24° | latitude: 32.86° | ||
magnitude:
| visual | 4.6 (observed) | source: 25 |
| photovisual | 4.8 | source: 2 |
| photographic | 4.8 | source: 16 |
spectral information:
| spectral class | F5 | source: 96 | |
| Morgan-Keenan | F6V | source: 25 | |
| B-magnitude | 5.06 ±0.05 | B-V-magnitude | 0.46 |
| U-magnitude | 5.06 ±0.05 | U-B-magnitude | 0 |
double/multiple star system information:
| separation between brightest and second brightest component | 65.7 arcsec |
| magnitude difference between brightest and second brightest component | 2.58 |
| position angle | 3 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4.6 | F5 | t1Hydrae, 31 Hya, HR 3759, HD 81997, SAO 136895 |
| B | 7.18 | - |
sources:
| 2 | HD and HDE Catalogs |
| Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University | |
| 16 | PPM North and PPM South Catalogs and PPM Supplement |
| Roser, S., and U. Bastian, "Catalogue of Positions and Proper Motions," A&AS, Vol. 74, p. 449, 1988, and Bastian, U., et al., "Catalogue of Positions and Proper Motions - South," 1993 | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 25 | Bright Star Catalogue, 5th edition |
| Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994 | |
| 52 | PPMN-HP subset |
| PPMN Star Catalogue (Reference 16) High-Precision Subset (Code H) | |
| 96 | SAO or HD/HDE Catalog |
| Reference from Value 1 or Reference from Value 2 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (B1950) | RA: 9h 26min 36.618sec | DEC: -2° 32' 58.04'' | ±0.016 arcsec |
| position (J2000) | RA: 9h 29min 8.884sec | DEC: -2° 46' 8.22'' | |
| proper motion B1950 (FK4) | RA: 0.0084 arcsec/a | DEC: -0.018 arcsec/a | ±0.004 arcsec/a in RA ±0.003 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0.0086 arcsec/a | DEC: -0.015 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 4.8 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | F5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | GC, catalogue number: 13080 |
| Durchmusterung | BD-02 2901 |
| Boss General Catalogue | 13080 |
| Henry Draper Catalogue | 81997 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 9h 29.1min | DEC: -2° 46' |
| proper motion (J2000) | RA: 0.134 arcsec/a | DEC: -0.022 arcsec/a |
double/multiple star system information:
| component | year | number of measures | position angle | angular separation | magnitude of 1st component | magnitude of 2nd component | spectral class(es) | discoverer code |
| - | 1821 | 14 | 3° | 65.7'' | 4.6 | 7.18 | F6V | HJ 1167 |
discoverer information:
| discoverer code | discoverer | reference |
| HJ 1167 | Herschel, J. | - |
notes:
| note | Tau (1) Hya. B is BD-02@2902. Proper motion of B +145 -025. |