| Identification Data |
| Common Name | Castor |
| Constellation | Gemini |
| Star Name | 66alp Gem |
| Skymap Number | 7340280 |
| Henry Draper (HD) Number | 60179 |
| Harvard Revised (HR) Number | 2891 |
| SAO Number | 60198 |
| Durchmusterung (DM) Number | BD+32 1581 |
Washington Double Stars (WDS) Number
| 07346+3153
|
| Positional Data |
| Position and Proper Motion (PPM) Number | |
| Right Ascension (RA) J2000 | 7h 34m 35.862s |
| Declination (Dec) J2000 | +31° 53' 17.795" |
| Position Uncertainty | 0.0191s |
| Proper Motion in RA (J2000)/cos(Dec) | -0.01620 |
| Proper Motion in Dec (J2000) | -0.148267 |
| Radial Velocity | +006.km s-1 |
| Trigonometric Parallax | +0.06327s |
| Trigonometric Parallax Uncertainty | 0.00123s |
| GCI Unit Vector in X (J2000) | -0.340599 |
| GCI Unit Vector in Y (J2000) | 0.777772 |
| GCI Unit Vector in Z (J2000) | 0.528265 |
| Galactic Longitude | 187.45° |
Galactic Latitude
| 22.48°
|
| Observational Data |
| Observed Visual Magnitude (V) | 1.58 |
| Derived Visual Magnitude | |
| Derived Visual Magnitude or Observed Visual Magnitude Uncertainty | |
| Observed B Magnitude | 1.61 |
| Observed B-V Colour | +0.034 |
| Observed B Magnitude or (B-V) Magnitude Uncertainty | 0.002 |
| Observed U Magnitude | |
| Observed U-B Colour | |
| Observed U Magnitude or (U-B) Magnitude Uncertainty | |
| Observed Photovisual Magnitude | 2.0 |
| Observed Photographic Magnitude | 2.0 |
| Morgan Keenan (MK) Spectral Type | A1V |
| One-Dimensional Spectral Class | |
| Position Angle | 73 |
| Year of Observation | 1992. AD |