| Identification Data |
| Common Name | |
| Constellation | Cetus |
| Star Name | 21 Cet |
| Skymap Number | 540044 |
| Henry Draper (HD) Number | 5268 |
| Harvard Revised (HR) Number | 255 |
| SAO Number | 129019 |
| Durchmusterung (DM) Number | SD-09 181 |
Washington Double Stars (WDS) Number
|
|
| Positional Data |
| Position and Proper Motion (PPM) Number | 182801 |
| Right Ascension (RA) J2000 | 0h 54m 17.592s |
| Declination (Dec) J2000 | -8° 44' 26.382" |
| Position Uncertainty | 0.0076s |
| Proper Motion in RA (J2000)/cos(Dec) | +0.00115 |
| Proper Motion in Dec (J2000) | -0.047366 |
| Radial Velocity | +045.0km s-1 |
| Trigonometric Parallax | +0.00860s |
| Trigonometric Parallax Uncertainty | 0.00079s |
| GCI Unit Vector in X (J2000) | 0.960781 |
| GCI Unit Vector in Y (J2000) | 0.231964 |
| GCI Unit Vector in Z (J2000) | -0.151962 |
| Galactic Longitude | 125.19° |
Galactic Latitude
| -71.60°
|
| Observational Data |
| Observed Visual Magnitude (V) | 6.16 |
| Derived Visual Magnitude | |
| Derived Visual Magnitude or Observed Visual Magnitude Uncertainty | 0.005 |
| Observed B Magnitude | 7.08 |
| Observed B-V Colour | +0.917 |
| Observed B Magnitude or (B-V) Magnitude Uncertainty | 0.007 |
| Observed U Magnitude | |
| Observed U-B Colour | |
| Observed U Magnitude or (U-B) Magnitude Uncertainty | |
| Observed Photovisual Magnitude | 6.3 |
| Observed Photographic Magnitude | 6.9 |
| Morgan Keenan (MK) Spectral Type | G5IV |
| One-Dimensional Spectral Class | G0 |
| Position Angle | |
| Year of Observation | AD |