H Scorpii

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]

H Scorpii

H Scorpii and the dark clouds Barnard 231 Credit: DECaPS DR2
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]