Rho Cygni, a yellow giant star in Cygnus
Rho Cygni is a yellow giant star in the constellation Cygnus. At 126 light years away, it shines at an apparent visual magnitude of 4.02.
Rho Cygni (HIP 106481)
Rho Cygni is a yellow giant star in the constellation Cygnus. At 126 light years away, it shines at an apparent visual magnitude of 4.02. It is moving through the Galaxy at a speed of 19.0 km/s relative to the Sun.
Sky position: RA 21h 34.0m, Dec +45° 35.5'
Common designations: Rho Cygni, 73 Cygni, HR 8252, HD 205435, Gaia DR3 1971163631220899968, HIP 106481
Rho Cygni has the spectral type G8IIIFe-0.5. G-type stars are yellow stars of about 5,300 to 6,000 K, the same class as the Sun. Their spectra show strong lines of ionized calcium and many metals. 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 Rho Cygni in the sky
Rho Cygni lies in Cygnus. With a declination of +45° 35.5', it is visible from the entire Northern Hemisphere and from the Southern Hemisphere down to about latitude 44° S. Observers poleward of latitude 44° N see it as circumpolar: it never sets. 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 Rho Cygni
Astrometry and spectroscopy
| Right Ascension (J2000) | 323.49522102° (21h 34.0m) |
| Declination (J2000) | 45.59183890° (+45° 35.5') |
| Galactic Longitude | 90.74195483° |
| Galactic Latitude | -4.57955467° |
| Proper motion RA | -24.34 mas/yr |
| Proper motion Dec | -93.51 mas/yr |
| Parallax | 25.94 ± 0.10 mas |
| Spectral Type | G8IIIFe-0.5 |
| Radial Velocity | 6.88 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 5.47 | 2.54 |
| B | 4.91 | 1.98 |
| V | 4.02 | 1.09 |
| R | 3.31 | 0.38 |
| I | 2.81 | -0.12 |
| J | 2.47 | -0.46 |
| H | 2.06 | -0.87 |
| K | 1.96 | -0.97 |
Colour index B-V: +0.89
Derivations
- Heliocentric distance: 38.56 pc (126 light years) (0.4% margin of error)
- Absolute visual magnitude: 1.09
- Transverse velocity: 17.7 km/s
- Space velocity relative to the Sun: 19.0 km/s
- Galactic position (X, Y, Z): -0.5 pc, 38.4 pc, -3.1 pc
- Galactic velocity (U, V, W): 14.8 km/s, 6.3 km/s, -10.1 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.