HD 220689
HD 220689 is a single star in the equatorial constellation of Aquarius. It is a challenge to view with the naked eye, having an apparent visual magnitude of +7.74, but is readily viewed with a pair of binoculars. The star is located at a distance of 153 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s. A survey in 2015 has ruled out the existence of any additional stellar companions at projected distances from 26 to 305 astronomical units.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 25m 52.99170s |
| Declination | –20° 36′ 57.6998″ |
| Apparent magnitude (V) | +7.74 |
| Characteristics | |
| Spectral type | G3V |
| B−V color index | +0.603±0.002 |
| Astrometry | |
| Radial velocity (Rv) | +12.30±0.14 km/s |
| Proper motion (μ) | RA: –15.328 mas/yr Dec.: –177.593 mas/yr |
| Parallax (π) | 21.3074 ± 0.0236 mas |
| Distance | 153.1 ± 0.2 ly (46.93 ± 0.05 pc) |
| Absolute magnitude (MV) | 4.50 |
| Details | |
| Mass | 1.016±0.048 M☉ |
| Radius | 1.068±0.047 R☉ |
| Luminosity | 1.491±0.005 L☉ |
| Surface gravity (log g) | 4.360±0.045 cgs |
| Temperature | 5,921±26 K |
| Metallicity [Fe/H] | −0.07±0.10 dex |
| Rotation | ~29 d |
| Rotational velocity (v sin i) | 5.5 km/s |
| Age | 4.586±2.487 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The stellar classification of HD 220689 is G3V, matching a yellow hued G-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly 4.6 billion years old and is spinning with a projected rotational velocity of 5.5 km/s, giving it a rotation period of around 29 days. The star has a similar size, mass, and elemental abundances as the Sun. It is radiating 1.5 times the luminosity of the Sun from its photosphere at an effective temperature of 5,921 K.