25 Aquarii, an orange giant star in Aquarius
25 Aquarii is an orange giant star in the constellation Aquarius. At 247 light years away, it shines at an apparent visual magnitude of 5.10.
25 Aquarii (HIP 106944)
25 Aquarii is an orange giant star in the constellation Aquarius. At 247 light years away, it shines at an apparent visual magnitude of 5.10. It is moving through the Galaxy at a speed of 47.1 km/s relative to the Sun.
Sky position: RA 21h 39.6m, Dec +2° 14.6'
Common designations: 25 Aquarii, 6 Pegasi, d Aquarii, HR 8277, HD 206067, Gaia DR3 2694414129322277504, HIP 106944
25 Aquarii has the spectral type K0III. K-type stars are orange stars with surface temperatures of about 3,900 to 5,300 K. Their spectra are rich in neutral metal lines and, in the cooler examples, molecular bands. Its luminosity class III marks it as a giant: an evolved star that has left the main sequence and swollen to many times its original size.
How to find 25 Aquarii in the sky
25 Aquarii lies in Aquarius. With a declination of +2° 14.6', it is visible from the entire Northern Hemisphere and from the Southern Hemisphere down to about latitude 88° S. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around September, which makes the weeks around that month the best time to observe it.
Tabulated data for 25 Aquarii
Astrometry and spectroscopy
| Right Ascension (J2000) | 324.88861330° (21h 39.6m) |
| Declination (J2000) | 2.24356093° (+2° 14.6') |
| Galactic Longitude | 57.53639615° |
| Galactic Latitude | -35.27820367° |
| Proper motion RA | -30.18 mas/yr |
| Proper motion Dec | -83.64 mas/yr |
| Parallax | 13.22 ± 0.09 mas |
| Spectral Type | K0III |
| Radial Velocity | -34.63 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| B | 6.14 | 1.74 |
| V | 5.10 | 0.71 |
| J | 3.51 | -0.89 |
| H | 2.91 | -1.49 |
| K | 2.83 | -1.57 |
Colour index B-V: +1.04
Derivations
- Heliocentric distance: 75.67 pc (247 light years) (0.7% margin of error)
- Absolute visual magnitude: 0.71
- Transverse velocity: 31.9 km/s
- Space velocity relative to the Sun: 47.1 km/s
- Galactic position (X, Y, Z): 33.2 pc, 52.1 pc, -43.7 pc
- Galactic velocity (U, V, W): 7.9 km/s, -44.6 km/s, 12.8 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.