98 Herculis

98 Herculis is a single^[7] star located approximately 590^[1] light years from the Sun in the northern constellation Hercules. It is visible to the naked eye as a dim, red-hued point of light with an apparent visual magnitude of 4.96.^[2] The brightness of the star is diminished by an extinction of 0.19 due to interstellar dust.^[8] The star is moving closer to the Earth with a heliocentric radial velocity of −19 km/s.^[2]

98 Herculis

Observation data Epoch J2000      Equinox J2000
Constellation	Hercules
Right ascension	18h 06m 01.90000s[1]
Declination	+22° 13′ 07.9396″[1]
Apparent magnitude (V)	4.96[2]
Characteristics
Evolutionary stage	AGB
Spectral type	M3-SIII[3] or M3IIIBa0.2[4]
B−V color index	1.656±0.062[2]
Variable type	suspected[5]
Astrometry
Radial velocity (Rv)	−19.48±0.21[2] km/s
Proper motion (μ)	RA: −12.028[1] mas/yr Dec.: −6.067[1] mas/yr
Parallax (π)	5.5201±0.1610 mas[1]
Distance	590 ± 20 ly (181 ± 5 pc)
Absolute magnitude (MV)	−1.78[2]
Details
Radius	85.39+10.72 −8.50[1] R☉
Luminosity	1,329.7±44.7[1] L☉
Temperature	3,772+203 −217[1] K
Other designations
98 Her, NSV 10208, BD+22°3273, HD 165625, HIP 88657, HR 6765, SAO 85725[6]
Database references
SIMBAD	data

This is an aging red giant star on the asymptotic giant branch^[9] with a stellar classification of M3-SIII,^[3] where the suffix notation indicating this is an S-type star. It is a mild barium star with an intensity class of 0.2,^[10][4] and is a suspected variable star, although Percy and Shepherd (1992) were unable to confirm this.^[11] With the hydrogen at its core exhausted, the star has expanded to around 85^[1] times the Sun's radius. It is radiating 1,330^[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,772 K.^[1]