H Scorpii
Star in the constellation Scorpius
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H Scorpii (H Sco) is a single[11] star in the southern constellation Scorpius. It is faintly visible to the naked eye with an apparent visual magnitude of 4.18.[2] The star is located at a distance of approximately 343 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −2 km/s.[5] This star was initially given the Bayer designation Beta Normae by Lacaille but it was later reassigned from Norma to Scorpius.[12]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 36m 22.47192s[1] |
| Declination | −35° 15′ 19.1803″[1] |
| Apparent magnitude (V) | 4.18[2] |
| Characteristics | |
| Evolutionary stage | giant[3] |
| Spectral type | K6III[4] |
| B−V color index | 1.535±0.069[2] |
| Astrometry | |
| Radial velocity (Rv) | −2.10±0.7[5] km/s |
| Proper motion (μ) | RA: 15.61±0.17 mas/yr[1] Dec.: 11.33±0.14 mas/yr[1] |
| Parallax (π) | 9.52±0.16 mas[1] |
| Distance | 343 ± 6 ly (105 ± 2 pc) |
| Absolute magnitude (MV) | −0.84±0.037[6] |
| Details | |
| Mass | 1.06+0.74 −0.28 M☉[7] 1.81[8] M☉ |
| Radius | 52.79±5.47[3] R☉ |
| Luminosity | 389 L☉[7] 562 L☉[8] 582±147[3] L☉ |
| Surface gravity (log g) | 1.30±0.15[3] cgs |
| Temperature | 3,875±21[8] K |
| Metallicity [Fe/H] | 0.00±0.20 dex[3] −0.30[7] dex |
| Rotational velocity (v sin i) | 3.1[9] km/s |
| Age | 2.18[8] Gyr |
| Other designations | |
| H Sco, NSV 7844, CD−34°11112, GC 22311, HD 149447, HIP 81304, HR 6166, SAO 207814, PPM 295235[10] | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K6III.[4] After exhausting the supply of hydrogen at its core, this star cooled and expanded off the main sequence. It now has around 53 times the radius of the Sun.[3] The star is about 2.2[8] billion years old with only a mild level of magnetic activity, and is spinning with a projected rotational velocity of 3.1 km/s.[9] It is radiating 4–600 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,875 K.[8]