Mu Ophiuchi

μ Ophiuchi, Latinized as Mu Ophiuchi, is a solitary,^[10] blue-white hued star in the equatorial constellation of Ophiuchus. It is visible to the naked as a faint point of light with an apparent visual magnitude of 4.62.^[2] This object is located approximately 760 light years away from the Sun based on parallax,^[5] but is drifting closer with a radial velocity of −18.5 km/s.^[4]

Mu Ophiuchi

Location of μ Ophiuchi (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Ophiuchus
Right ascension	17h 37m 50.71308s[1]
Declination	−08° 07′ 07.5749″[1]
Apparent magnitude (V)	4.62[2]
Characteristics
Spectral type	B8II-IIIp:Mn[3]
U−B color index	−0.20[2]
B−V color index	+0.11[2]
Astrometry
Radial velocity (Rv)	−18.50[4] km/s
Proper motion (μ)	RA: −11.31[5] mas/yr Dec.: −20.47[5] mas/yr
Parallax (π)	4.32±0.20 mas[5]
Distance	750 ± 30 ly (230 ± 10 pc)
Absolute magnitude (MV)	−2.24[6]
Details
Radius	11.1+2.1 −0.6[1] R☉
Luminosity	398.7±26.8[1] L☉
Temperature	7,748+210 −651[1] K
Metallicity [Fe/H]	+0.00[7] dex
Rotational velocity (v sin i)	95[8] km/s
Other designations
μ Oph, 57 Ophiuchi, BD−08°4472, FK5 3399, GC 23889, HD 159975, HIP 86284, HR 6567, SAO 141772[9]
Database references
SIMBAD	data

This object has a stellar classification of B8II-IIIp:Mn,^[3] showing a luminosity class with mixed traits of a giant or bright giant star. The suffix notation indicates it is a candidate chemically peculiar star with an overabundance of manganese in its spectrum. It may be a mercury-manganese star.^[11] This object has 11 times the radius of the Sun and is radiating nearly 400 times the Sun's luminosity from its photosphere at an effective temperature of 7,748 K.^[1] It is spinning with a projected rotational velocity of 95 km/s.^[8]

In 2006, a new nearby star cluster, Mamajek 2 (/ˈmæmədʒɛk/), was discovered. Mu Ophiuchi is a candidate member.^[12] The cluster has an estimated age of 120±25 million years.^[13]