| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 54m 45.47009s[1] |
| Declination | –16° 16′ 19.0505″[1] |
| Apparent magnitude (V) | 5.55[2] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K1 III[3] |
| U−Bcolor index | +1.089[2] |
| B−Vcolor index | +1.104[2] |
| Variable type | suspected[4] |
| Astrometry | |
| Radial velocity (Rv) | −34.59±0.16[1] km/s |
| Proper motion (μ) | RA: –222.505[1]mas/yr Dec.: –88.355[1]mas/yr |
| Parallax (π) | 24.1777±0.1211 mas[1] |
| Distance | 134.9 ± 0.7 ly (41.4 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.46[5] |
| Details | |
| Mass | 1.14[6] M☉ |
| Radius | 5.79+0.22 −0.21[1] R☉ |
| Luminosity | 13.347±0.085[1] L☉ |
| Surface gravity (log g) | 2.8[7] cgs |
| Temperature | 4,583+86 −83[1] K |
| Metallicity [Fe/H] | +0.03[7] dex |
| Rotational velocity (v sin i) | 3.9[7] km/s |
| Age | 7.61[6] Gyr |
| Other designations | |
| 70 Aqr,NSV 14358,BD−17°6619,HD 216640,HIP 113148,HR 8711,SAO 165376[8] | |
| Database references | |
| SIMBAD | data |
77 Aquarii is a single[9]star located 135 light years away from the Sun in theequatorialconstellation ofAquarius.77 Aquarii is itsFlamsteed designation. It is visible to the naked eye as a dim star with a baselineapparent visual magnitude of 5.55.[2] The star is moving closer to the Earth with a heliocentricradial velocity of −35 km/s.[1]
At the estimated age of 7.61[6] billion years old, this is an aginggiant star with astellar classification of K1 III.[3] It is a suspectedvariable star that ranges in brightness from a maximum of magnitude 5.53 down to 5.60.[4] 77 Aquarii has 1.14[6] times themass of the Sun and, after exhausting the hydrogen at itscore, has expanded to six times theSun's radius. It is radiating 13.3[1] times the Sun's luminosity from itsphotosphere at aneffective temperature of 4,581 K,[7] giving it the orange-hued glow of aK-type star.[10]
