Castor
| catalogues and names | Castor, a Gem, 66 Gem, HR 2890, HD 60178, SAO 60198, FK5: 287, WDS 07346+3153B |
| constellation | Gemini |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 7h 34min 36sec | DEC: +31° 53' 19'' |
| position (J1900) | RA: 7h 28min 13sec | DEC: +32° 6' 27'' |
| proper motion (J2000) | RA: -0,172 arcsec/a | DEC: -0,099 arcsec/a |
| radial velocity | -1 km/s note: spectroscopic binaries, single lined spectra note: orbital data avaible |
|
| rotational velocity | 30 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,067 arcsec | |
| note (category: dynamical parallaxes): | 0.052". |
magnitude
| visual magnitude | 2,88 (V on UBV Johnson system) |
spectral / color information
| spectral class | A2Vm |
| B-V-magnitude | 0,04 |
| U-B-magnitude | 0,02 |
| note (category: spectra): | K-line indicates A1, metallic lines A5. |
double/multiple star system information
| number of components of multiple star system | 6 |
| separation | 2 arcsec |
| mag difference (of double or brightest multiple) | 0,9 |
| component ID | AB |
| note (category: double and multiple data): | Binary with HR 2891. Combined colors. |
| note (category: spectroscopic binaries): | ADS 6175B, 2.9283d, K 31.9k/s, V0 -1.2k/s, asini 1.28. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 7h 34min 36,13sec | DEC: +31° 53' 19,43'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: -0,0135 arcsec/a | DEC: -0,099 arcsec/a | source: 25 | |
| radial velocity | -1 km/s | source: 25 | ||
| trigonometric parallax | 0,067 | ±0,007 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 187,45° | latitude: 22,48° | ||
| GCI unit vector (J2000) | X: -0,340613 | Y: 0,777761 | Z: 0,528271 | |
magnitude:
| visual | 2,88 (observed) | source: 25 |
| photovisual | 2,9 | source: 2 |
spectral information:
| spectral class | A0 | source: 96 | |
| Morgan-Keenan | A2Vm | source: 25 | |
| B-magnitude | 2,92 ±0,05 | B-V-magnitude | 0,04 |
| U-magnitude | 2,94 ±0,05 | U-B-magnitude | 0,02 |
double/multiple star system information:
| separation between brightest and second brightest component | 3,3 arcsec |
| magnitude difference between brightest and second brightest component | 0,9 |
| position angle | 73 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 1,98 | - | Castor, a Geminorum, 66 Gem, HR 2891, HD 60179, |
| B | 2,88 | A0 | Castor, a Geminorum, 66 Gem, HR 2890, HD 60178, SAO 60198 |
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: 7h 31min 24,654sec | DEC: +31° 59' 59,07'' | ±0,003 arcsec |
| position (J2000) | RA: 7h 34min 35,994sec | DEC: +31° 53' 18,54'' | |
| proper motion J1950 (FK4) | RA: -0,0134 arcsec/a | DEC: -0,102 arcsec/a | ±0,001 arcsec/a in RA ±0,001 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0,0135 arcsec/a | DEC: -0,098 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: 287 |
| Durchmusterung | BD+32 1581 |
| Boss General Catalogue | 10120 |
| Henry Draper Catalogue | 60178 The "SAO Catalog" entry refers to two consecutive HD numbers, the lower of which is given. |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 7h 34,6min | DEC: +31° 53' |
| proper motion (J2000) | RA: -0,172 arcsec/a | DEC: -0,099 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 | 1819 | often | 270° | 4,5'' | 2 | 2,9 | A1V A2Vm | STF1110 |
| 1992 | 73° | 3,3'' | ||||||
| AC | 1835 | often | 164° | 72,5'' | 2 | 8,8 | - | STF1110 |
| 1990 | - | 71,2'' | ||||||
| AD | 1902 | 2 | 222° | 204,4'' | 2 | - | - | STF1110 |
| BC | 1862 | 16 | 160° | 70,4'' | 2,9 | 8,7 | - | STF1110 |
| 1957 | 163° | 69,5'' |
discoverer information:
| discoverer code | discoverer | reference |
| STF1110 | Struve, F.G.W. | - |
notes:
| note | Alpha Gem. Castor. Mt. Wilson spectral types A2,A2,M1. P = 467yr., a = 6.80", motion retrograde. A and B are both spectroscopic binaries, and C is the eclipsing binary YY Gem, P =0.81d, so the object is sextuple. Castor A is also reported to exhibit x-ray and radio emission. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (J1900) | RA: 7h 28,2min | DEC: +32° 6' |
magnitudes, spectral classes, orbital elements:
| author: | P. Muller | W. Rabe |
| date of observation: | 1957 | |
| magnitude of component A: | 1,94 | 1,94 |
| magnitude of component B: | 1,94 | 1,94 |
| spectral class component B: | A1V | A1V |
| spectral class component B: | A1V | A1V |
| period [y]: | 511,3 | 420,07 |
| semi-major axis [arcsec]: | 7,369 | 6,295 |
| inclination [deg]: | 112,94 | 115,94 |
| node [deg]: | 41,65 (ascending) | 40,47 (ascending) |
| equinox of node: | 1900 | |
| eccentricity: | 0,36 | 0,33 |
| time of periastron passage: | 1950,65 | 1965,3 |
| dates of ephemeris: | 1950-1970 | 1957-1967 |
| grade: | reliable | reliable |
| reference: | Bull. Astron. 20, 145; 1956. | Astron. Nachr. 284, 101; 1958. |
| notes | Castor, a sextuple system. Both A and B are single-lined spectroscopic binaries with P = 9.21 d and 2.93 d, respectively. Star C (mag. 9.1, M1Ve) is the spectroscopic and detached eclipsing binary YY Gem (P = 0.81 d), 70" from the center of AB and in slow retrograde motion (cf. Heintz, Veroff. Sternw. Munchen 5, 93; 1960). |