Alphard
| catalogues and names | Alphard, a Hya, NSV 04496, 30 Hya, HR 3748, HD 81797, SAO 136871, FK5: 354, WDS 09276-0840A |
| other names | Alfard, Kalbelaphard, Cor Hydrae, Alphart, Alfard, Alphart, Kalbelaphard, Cor Hydrae |
| constellation | Hydra |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | ALPHARD; Alfard; Alphart; Kalbelaphard; Cor Hydrae. |
position, motion, parallax:
| position (J2000) | RA: 9h 27min 35,2sec | DEC: -8° 39' 31'' |
| position (J1900) | RA: 9h 22min 40,4sec | DEC: -8° 13' 30'' |
| proper motion (J2000) | RA: -0,014 arcsec/a | DEC: 0,033 arcsec/a |
| radial velocity | -4 km/s note: suspected variable radial velocity |
|
| rotational velocity | <17 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,022 arcsec | |
magnitude
| visual magnitude | 1,98 (V on UBV Johnson system) |
spectral / color information
| spectral class | K3II-III |
| B-V-magnitude | 1,44 |
| U-B-magnitude | 1,72 |
| R-I-magnitude | 0,77 |
| note (category: spectra): | Balloon-borne spectrometer revealed pronounced emission of MgII. |
variability information
| variable star identification | 4496 |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 283,1 arcsec |
| mag difference (of double or brightest multiple) | 7,5 |
| component ID | AB |
| note | Worley (1978) update of the IDS |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 9h 27min 35,247sec | DEC: -8° 39' 31,15'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: -0,0009 arcsec/a | DEC: 0,033 arcsec/a | source: 25 | |
| radial velocity | -4 km/s | source: 25 | ||
| trigonometric parallax | 0,022 | ±0,002 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 241,5° | latitude: 29,05° | ||
| GCI unit vector (J2000) | X: -0,777933 | Y: 0,610046 | Z: -0,150547 | |
magnitude:
| visual | 1,98 (observed) | source: 25 |
| photovisual | 2,2 | source: 2 |
| photographic | 3,2 | source: 2 |
spectral information:
| spectral class | K2 | source: 96 | |
| Morgan-Keenan | K3II-III | source: 25 | |
| B-magnitude | 3,42 ±0,05 | B-V-magnitude | 1,44 |
| U-magnitude | 5,14 ±0,05 | U-B-magnitude | 1,72 |
double/multiple star system information:
| separation between brightest and second brightest component | 283,1 arcsec |
| magnitude difference between brightest and second brightest component | 7,7 |
| position angle | 153 ° |
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 | |
| 15 | FK5, FK5 Extension and FK5 Supplement |
| Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 1991 | |
| 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 | |
| 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 (J1950) | RA: 9h 25min 7,791sec | DEC: -8° 26' 27,47'' | ±0,003 arcsec |
| position (J2000) | RA: 9h 27min 35,254sec | DEC: -8° 39' 31,17'' | |
| proper motion J1950 (FK4) | RA: -0,0012 arcsec/a | DEC: 0,028 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0008 arcsec/a | DEC: 0,033 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 2,2 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | K2 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 354 |
| Durchmusterung | BD-08 2680 |
| Boss General Catalogue | 13044 |
| Henry Draper Catalogue | 81797 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 9h 27,6min | DEC: -8° 40' |
| proper motion (J2000) | RA: -0,014 arcsec/a | DEC: 0,033 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 |
| AB | 1841 | 4 | 153° | 283,1'' | 1,98 | 9,7 | K3II-III | H 111 |
| AC | 1783 | 1 | F° | 210'' | 2,2 | - | - | H 111 |
discoverer information:
| discoverer code | discoverer | reference |
| H 111 | Herschel, W. | - |
notes:
| note | AB: H VI 111. Alpha Hya. B is BD-08@2681. |
data from Combined General Catalogue of Variable Stars (suspected variables) (Kholopov+ 1998)
position:
| position (J1950) | RA: 9h 25min 7,8sec | DEC: -8° 26' 27'' |
variability informations:
| magnitute at max. brightness | 1,93 |
| magnitute at min. brightness | 2,01 |
| photometric system | visual, photovisual or Johnson's V |
spectral information
| spectral class | K3 |
references
| to a study | 0832D (designation: ALPHA HYA) |
miscanellous
| There are notes in the published catalog (Kukarkin et al.(1982)). |