| Identification Data |
| Common Name | |
| Constellation | Coma Berenices |
| Star Name | 21 Com |
| Skymap Number | 12310002 |
| Henry Draper (HD) Number | 108945 |
| Harvard Revised (HR) Number | 4766 |
| SAO Number | 82346 |
| Durchmusterung (DM) Number | BD+25 2517 |
Washington Double Stars (WDS) Number
|
|
| Positional Data |
| Position and Proper Motion (PPM) Number | 101953 |
| Right Ascension (RA) J2000 | 12h 31m 0.560s |
| Declination (Dec) J2000 | +24° 34' 1.804" |
| Position Uncertainty | 0.0094s |
| Proper Motion in RA (J2000)/cos(Dec) | -0.00088 |
| Proper Motion in Dec (J2000) | -0.008966 |
| Radial Velocity | +000.1km s-1 |
| Trigonometric Parallax | +0.01049s |
| Trigonometric Parallax Uncertainty | 0.00083s |
| GCI Unit Vector in X (J2000) | -0.901162 |
| GCI Unit Vector in Y (J2000) | -0.122680 |
| GCI Unit Vector in Z (J2000) | 0.415760 |
| Galactic Longitude | 241.01° |
Galactic Latitude
| 84.74°
|
| Observational Data |
| Observed Visual Magnitude (V) | 5.44 |
| Derived Visual Magnitude | |
| Derived Visual Magnitude or Observed Visual Magnitude Uncertainty | 0.003 |
| Observed B Magnitude | 5.51 |
| Observed B-V Colour | +0.065 |
| Observed B Magnitude or (B-V) Magnitude Uncertainty | 0.004 |
| Observed U Magnitude | |
| Observed U-B Colour | |
| Observed U Magnitude or (U-B) Magnitude Uncertainty | |
| Observed Photovisual Magnitude | 5.4 |
| Observed Photographic Magnitude | 5.5 |
| Morgan Keenan (MK) Spectral Type | A2p |
| One-Dimensional Spectral Class | A3 |
| Position Angle | |
| Year of Observation | AD |