| Identification Data |
| Common Name | |
| Constellation | Perseus |
| Star Name | 21 Per |
| Skymap Number | 2570048 |
| Henry Draper (HD) Number | 18296 |
| Harvard Revised (HR) Number | 873 |
| SAO Number | 56031 |
| Durchmusterung (DM) Number | BD+31 509 |
Washington Double Stars (WDS) Number
|
|
| Positional Data |
| Position and Proper Motion (PPM) Number | 67948 |
| Right Ascension (RA) J2000 | 2h 57m 17.282s |
| Declination (Dec) J2000 | +31° 56' 3.187" |
| Position Uncertainty | 0.0094s |
| Proper Motion in RA (J2000)/cos(Dec) | +0.00024 |
| Proper Motion in Dec (J2000) | -0.031166 |
| Radial Velocity | +007.7km s-1 |
| Trigonometric Parallax | +0.00843s |
| Trigonometric Parallax Uncertainty | 0.00090s |
| GCI Unit Vector in X (J2000) | 0.607149 |
| GCI Unit Vector in Y (J2000) | 0.592948 |
| GCI Unit Vector in Z (J2000) | 0.528945 |
| Galactic Longitude | 151.89° |
Galactic Latitude
| -23.77°
|
| Observational Data |
| Observed Visual Magnitude (V) | 5.10 |
| Derived Visual Magnitude | |
| Derived Visual Magnitude or Observed Visual Magnitude Uncertainty | 0.004 |
| Observed B Magnitude | 5.09 |
| Observed B-V Colour | -0.013 |
| 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 | 5.2 |
| Observed Photographic Magnitude | |
| Morgan Keenan (MK) Spectral Type | B9pSi |
| One-Dimensional Spectral Class | A0 |
| Position Angle | |
| Year of Observation | AD |
