| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h34m 46.58574s[1] |
| Declination | +38° 32′ 02.6267″[1] |
| Apparent magnitude (V) | 4.87[2] |
| Characteristics | |
| Spectral type | K0.5 III Fe0.5[3]orK0.5 III CN 0.5[4] + M5[5] |
| B−V color index | 1.092[6] |
| Astrometry | |
| Radial velocity (Rv) | −68.12±0.11[6] km/s |
| Proper motion (μ) | RA: +113.665[1] mas/yr Dec.: +100.403[1] mas/yr |
| Parallax (π) | 14.2468 ± 0.1339 mas[1] |
| Distance | 229 ± 2 ly (70.2 ± 0.7 pc) |
| Absolute magnitude (MV) | 0.62[2] |
| Details | |
| Mass | 1.70[7] M☉ |
| Radius | 14[6] R☉ |
| Luminosity | 69[7] L☉ |
| Surface gravity (log g) | 2.68±0.04[8] cgs |
| Temperature | 4,640±25[7] K |
| Metallicity [Fe/H] | 0.18[8] dex |
| Rotational velocity (v sin i) | 1.4[6] km/s |
| Age | 900±200[8] Myr |
| Other designations | |
72 Cyg, BD+37°4359, FK5 3722, HD 205512, HIP 106551, HR 8255, SAO 71480[9] | |
| Database references | |
| SIMBAD | data |
72 Cygni is a star in the northern constellationofCygnus, located 299 light years from the Sun[1] and a member of the Hercules stream.[8] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.87.[2] 72 Cyg is moving closer to the Earth with a heliocentric radial velocity of −68 km/s.[6] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.154″ per year.[10]
This is an aging giant star with a stellar classificationofK0.5 III Fe0.5,[3] where the suffix notation indicates a mild underabundance of iron in the spectrum. It has 1.7[7] times the mass of the Sun but has expanded to 14[6] times the Sun's radius. The star is radiating 69[7] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,640 K.[7]
72 Cygni has a wide companion at an angular separationof66.1″, corresponding to a projected separationof4,690 AU. This star has a J band (infrared) magnitude of 13.224±0.025 and a class of M5.[5]
