44 Ophiuchi
44 Ophiuchi is a single star in the constellation Ophiuchus. It has the Bayer designation b Ophiuchi, while 44 Ophiuchi is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.16. The distance to this object is approximately 83.2 light years based on parallax. It is drifting closer to the Earth with a heliocentric radial velocity of -37.2 km/s, and is predicted to come within 30 light-years around 585,000 years from now.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 26m 22.21749s |
| Declination | −24° 10′ 31.1190″ |
| Apparent magnitude (V) | 4.16 |
| Characteristics | |
| Spectral type | kA5hA9mF1III |
| U−B color index | +0.12 |
| B−V color index | +0.28 |
| Astrometry | |
| Radial velocity (Rv) | −37.20 km/s |
| Proper motion (μ) | RA: +0.10 mas/yr Dec.: −118.18 mas/yr |
| Parallax (π) | 39.22 ± 0.24 mas |
| Distance | 83.2 ± 0.5 ly (25.5 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.13 |
| Details | |
| Mass | 1.77 M☉ |
| Radius | 1.9 R☉ |
| Luminosity | 13 L☉ |
| Surface gravity (log g) | 4.15 cgs |
| Temperature | 7,559 K |
| Metallicity [Fe/H] | +0.30 dex |
| Rotational velocity (v sin i) | 78 km/s |
| Age | 1.028 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an Am star with a stellar classification of kA5hA9mF1III, indicating it has the luminosity class of a giant star with a spectrum that matches an A5 star based on the calcium K line, and an A9 star from the hydrogen and metal lines. It is around a billion years old with 1.77 times the mass of the Sun and 1.9 times the Sun's girth. The star is radiating 13 times the Sun's luminosity from its photosphere at an effective temperature of 7,559 K. It retains a moderately high rotation rate, showing a projected rotational velocity of 78 km/s.