HD 131551
Star in the constellation Apus
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HD 131551 (HR 5555) is a solitary star in the southern constellation Apus. It has an apparent magnitude of 6.19,[3] 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.[7]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Apus[1] |
| Right ascension | 14h 59m 55.7597s[2] |
| Declination | −75° 01′ 57.6124″[2] |
| Apparent magnitude (V) | 6.19±0.01[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4][2] |
| Spectral type | B9 V[5] |
| U−B color index | −0.19[6] |
| B−V color index | −0.04[6] |
| Astrometry | |
| Radial velocity (Rv) | −7.6±1.7[7] km/s |
| Proper motion (μ) | RA: −5.659[2] mas/yr Dec.: −20.787[2] mas/yr |
| Parallax (π) | 6.198±0.04 mas[2] |
| Distance | 526 ± 3 ly (161 ± 1 pc) |
| Absolute magnitude (MV) | +0.3[8] |
| Details | |
| Mass | 2.84±0.06[4] M☉ |
| Radius | 3.19[9] R☉ |
| Luminosity | 100[10] L☉ |
| Surface gravity (log g) | 3.86[9] cgs |
| Temperature | 10,651[10] K |
| Metallicity [Fe/H] | 0.00[11] dex |
| Rotational velocity (v sin i) | 141[12] km/s |
| Age | 254[11] Myr |
| Other designations | |
| 20 G. Apodis, CD−74°947, CPD−74°1281, GC 20110, HD 131551, HIP 73394, HR 5555, SAO 257219, WDS J14599-7502A | |
| Database references | |
| SIMBAD | data |
HD 131551 has a stellar classification of B9 V, indicating that it is an ordinary B-type main-sequence star.[5] At present it has 2.84 times the mass of the Sun[4] and a radius of 3.19 R☉.[9] It shines at 100 times the luminosity of the Sun[10] from its photosphere at an effective temperature of 10,651 K,[10] giving it a blue-white hue. This object is 254 million years old[11] – having completed 70.1%[4] of its main sequence lifetime – and is spinning rapidly with a projected rotational velocity of 141 km/s.[12] HD 131551 has a similar metallicity compared to the Sun.[11]
There is a 13th magnitude companion star at an angular separation of 34.5″ along a position angle of 123° (as of 2010).[13]