| Identification Data |
| Common Name | Asellus Secondus |
| Constellation | Boötes |
| Star Name | 21iot Boo |
| Skymap Number | 14160031 |
| Henry Draper (HD) Number | 125161 |
| Harvard Revised (HR) Number | 5350 |
| SAO Number | 29071 |
| Durchmusterung (DM) Number | BD+52 1784 |
Washington Double Stars (WDS) Number
| 14162+5122
|
| Positional Data |
| Position and Proper Motion (PPM) Number | 34432 |
| Right Ascension (RA) J2000 | 14h 16m 9.929s |
| Declination (Dec) J2000 | +51° 22' 2.033" |
| Position Uncertainty | 0.0064s |
| Proper Motion in RA (J2000)/cos(Dec) | -0.01602 |
| Proper Motion in Dec (J2000) | +0.089466 |
| Radial Velocity | -018.7km s-1 |
| Trigonometric Parallax | +0.03354s |
| Trigonometric Parallax Uncertainty | 0.00056s |
| GCI Unit Vector in X (J2000) | -0.517338 |
| GCI Unit Vector in Y (J2000) | -0.349493 |
| GCI Unit Vector in Z (J2000) | 0.781164 |
| Galactic Longitude | 95.22° |
Galactic Latitude
| 60.96°
|
| Observational Data |
| Observed Visual Magnitude (V) | 4.75 |
| Derived Visual Magnitude | |
| Derived Visual Magnitude or Observed Visual Magnitude Uncertainty | 0.002 |
| Observed B Magnitude | 4.98 |
| Observed B-V Colour | +0.227 |
| Observed B Magnitude or (B-V) Magnitude Uncertainty | 0.003 |
| Observed U Magnitude | |
| Observed U-B Colour | |
| Observed U Magnitude or (U-B) Magnitude Uncertainty | |
| Observed Photovisual Magnitude | 4.8 |
| Observed Photographic Magnitude | |
| Morgan Keenan (MK) Spectral Type | A9V |
| One-Dimensional Spectral Class | A5 |
| Position Angle | 33 |
| Year of Observation | 1964. AD |