| Identification Data |
| Common Name | |
| Constellation | Cassiopeia |
| Star Name | 21 Cas |
| Skymap Number | 450088 |
| Henry Draper (HD) Number | 4161 |
| Harvard Revised (HR) Number | 192 |
| SAO Number | 4216 |
| Durchmusterung (DM) Number | BD+74 27 |
Washington Double Stars (WDS) Number
| 00457+7459
|
| Positional Data |
| Position and Proper Motion (PPM) Number | 4492 |
| Right Ascension (RA) J2000 | 0h 45m 39.077s |
| Declination (Dec) J2000 | +74° 59' 17.063" |
| Position Uncertainty | 0.0061s |
| Proper Motion in RA (J2000)/cos(Dec) | -0.00384 |
| Proper Motion in Dec (J2000) | -0.021966 |
| Radial Velocity | +008.9km s-1 |
| Trigonometric Parallax | +0.01124s |
| Trigonometric Parallax Uncertainty | 0.00055s |
| GCI Unit Vector in X (J2000) | 0.253898 |
| GCI Unit Vector in Y (J2000) | 0.051254 |
| GCI Unit Vector in Z (J2000) | 0.965872 |
| Galactic Longitude | 122.55° |
Galactic Latitude
| 12.12°
|
| Observational Data |
| Observed Visual Magnitude (V) | 5.65 |
| Derived Visual Magnitude | |
| Derived Visual Magnitude or Observed Visual Magnitude Uncertainty | 0.003 |
| Observed B Magnitude | 5.72 |
| Observed B-V Colour | +0.067 |
| 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 | 5.6 |
| Observed Photographic Magnitude | |
| Morgan Keenan (MK) Spectral Type | A2IV |
| One-Dimensional Spectral Class | A2 |
| Position Angle | 160 |
| Year of Observation | 1962. AD |
