Sirius
| catalogues and names | Sirius, a CMa, NSV 17173, 9 CMa, HR 2491, HD 48915, SAO 151881, FK5: 257, WDS 06451-1643A |
| other names | Canicula, Dog Star, Aschere |
| constellation | Canis Major |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | SIRIUS; Canicula; Dog Star; Aschere. |
position, motion, parallax:
| position (J2000) | RA: 6h 45min 8,9sec | DEC: -16° 42' 58'' |
| position (J1900) | RA: 6h 40min 44,6sec | DEC: -16° 34' 44'' |
| proper motion (J2000) | RA: -0,553 arcsec/a | DEC: -1,205 arcsec/a |
| radial velocity | -8 km/s note: spectroscopic binaries note: orbital data avaible |
|
| rotational velocity | 13 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,375 arcsec | |
| note (category: dynamical parallaxes): | 0.376". |
magnitude
| visual magnitude | -1,46 (V on UBV Johnson system) |
spectral / color information
| spectral class | A1Vm |
| B-V-magnitude | 0 |
| U-B-magnitude | -0,05 |
| R-I-magnitude | -0,03 |
| note (category: spectra): | Cadmium discovered in spectra from COPERNICUS. Iron overabundant by a factor of 5 in comparison with Sun and titanium by a factor of 2. Possibility that the atmosphere of Sirius A polluted by material ejected from Sirius B. Weak magnetic field. Barium abundance greater than solar abundance by about 1.76. Also classified A/A0/A1. |
| note (category: colors): | Color excess E(B-V) = -0.03. |
double/multiple star system information
| number of components of multiple star system | 4 |
| separation | 11,2 arcsec |
| mag difference (of double or brightest multiple) | 10,3 |
| component ID | AB |
| note (category: double and multiple data): | AB -1.46 A1V, 8.49 A1V, 50.090y, a = 7.500" or 49.94y, a = 7.62". D, 14.0v at 32" from A. C, companion to B at 1.4" suspected but not confirmed. B is first white dwarf ever discovered; predicted by Bessel (1844) on basis of orbital motion of Sirius, it was first seen by Alvan Clark in 1862, and its peculiar high temperature, small size and great density established by W. Adams in 1925. |
| note (category: spectroscopic binaries): | 50.04y D, K 2.4k/s, V0 -7.6k/s, asini 487. |
miscellaneous information
| note (category: group membership): | Sirius group; UMa stream. |
| note (category: stellar radii or diameters): | Diam. = 0.00560 - 0.00589". |
| note (category: miscellaneous): | Soft X-rays observed from Astronomical Netherlands Satellite (ANS). Sirius B not unusual compared with other dA white dwarfs. Effective temperature about 32000K. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 6h 45min 8,821sec | DEC: -16° 42' 56,85'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: -0,0385 arcsec/a | DEC: -1,205 arcsec/a | source: 25 | |
| radial velocity | -8 km/s | source: 25 | ||
| trigonometric parallax | 0,375 | ±0,037 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 227,22° | latitude: -8,88° | ||
| GCI unit vector (J2000) | X: -0,187449 | Y: 0,93922 | Z: -0,287625 | |
magnitude:
| visual | -1,46 (observed) | source: 25 |
| photovisual | -1,6 | source: 2 |
| photographic | -1,6 | source: 2 |
spectral information:
| spectral class | A0 | source: 96 | |
| Morgan-Keenan | A1Vm | source: 25 | |
| B-magnitude | -1,46 ±0,05 | B-V-magnitude | 0 |
| U-magnitude | -1,51 ±0,05 | U-B-magnitude | -0,05 |
double/multiple star system information:
| magnitude difference between brightest and second brightest component | 10 |
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: 6h 42min 56,713sec | DEC: -16° 38' 46,37'' | ±0,003 arcsec |
| position (J2000) | RA: 6h 45min 8,917sec | DEC: -16° 42' 58,11'' | |
| proper motion J1950 (FK4) | RA: -0,0379 arcsec/a | DEC: -1,211 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0379 arcsec/a | DEC: -1,206 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | -1,6 (accuracy: 2 decimals) |
| source of visual magnitude data | Combined magnitude of component stars. |
spectral information:
| spectral class | A0 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Double star - see source catalog for source |
catalogues
| source catalogue | FK4, catalogue number: 257 |
| Durchmusterung | BD-16 1591 |
| Boss General Catalogue | 8833 |
| Henry Draper Catalogue | 48915 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 6h 45,1min | DEC: -16° 43' |
| proper motion (J2000) | RA: -0,553 arcsec/a | DEC: 0 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 | 1861 | often | ° | '' | -1,46 | 8,5 | A1Vm | AGC 1 |
| AD | 1865 | 2 | 170° | 44,3'' | - | 14 | A0 | AGC 1 |
| 1915 | 183° | 31,6'' | ||||||
| AE | 1877 | 1 | 115° | 71,4'' | - | - | - | HL 3 |
| AF | 1877 | 4 | 159° | 103,7'' | - | - | - | BU 1411 |
| BC | 1920 | 7 | 69° | 1,8'' | - | - | - | AGC 1 |
| 1929 | 129° | 1,4'' |
discoverer information:
| discoverer code | discoverer | reference |
| AGC 1 | - | - |
| HL 3 | Hall, A. | - |
| BU 1411 | Burnham, S.W. | - |
notes:
| note | AB: Sirius. Magnitude of A -1.58. Proper motion of A -553 -1205. P = 50.1yr., a = 7.50", motion retrograde. BC: Suspected by Fox in 1920, also reported by Innes, van den Bos, and Finsen. Oother observers fail to confirm duplicity of B. Single 1945, 1946, 1949, 1950. |