HD 131551
HD 131551 (HR 5555) is a solitary star in the southern constellation Apus. It has an apparent magnitude of 6.19, allowing it to be faintly seen with the naked eye under ideal conditions. Located 526 light years away, the object is approaching the Sun with a heliocentric radial velocity of 7.6 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Apus |
| Right ascension | 14h 59m 55.7597s |
| Declination | −75° 01′ 57.6124″ |
| Apparent magnitude (V) | 6.19±0.01 |
| Characteristics | |
| Spectral type | B9 V |
| U−B color index | −0.19 |
| B−V color index | −0.04 |
| Astrometry | |
| Radial velocity (Rv) | −7.6±1.7 km/s |
| Proper motion (μ) | RA: −5.659 mas/yr Dec.: −20.787 mas/yr |
| Parallax (π) | 6.198 ± 0.04 mas |
| Distance | 526 ± 3 ly (161 ± 1 pc) |
| Absolute magnitude (MV) | +0.3 |
| Details | |
| Mass | 2.84±0.06 M☉ |
| Radius | 3.19 R☉ |
| Luminosity | 100 L☉ |
| Surface gravity (log g) | 3.86 cgs |
| Temperature | 10,651 K |
| Metallicity [Fe/H] | 0.00 dex |
| Rotational velocity (v sin i) | 141 km/s |
| Age | 254 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 131551 has a stellar classification of B9 V, indicating that it is an ordinary B-type main-sequence star. At present it has 2.84 times the mass of the Sun and a radius of 3.19 R☉. It shines at 100 times the luminosity of the Sun from its photosphere at an effective temperature of 10,651 K, giving it a blue-white hue. This object is 254 million years old – having completed 70.1% of its main sequence lifetime – and is spinning rapidly with a projected rotational velocity of 141 km/s. HD 131551 has a similar metallicity compared to the Sun.
There is a 13th magnitude companion star at an angular separation of 34.5″ along a position angle of 123° (as of 2010).