Mu Normae

μ Normae, Latinised as Mu Normae, is a blue supergiant star of spectral type O9.7 Iab, located in the constellation of Norma.

A light curve for Mu Normae, plotted from TESS data^[11]

μ Normae

Location of μ Nor (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Norma
Right ascension	16h 34m 05.01936s[1]
Declination	−44° 02′ 43.1206″[1]
Apparent magnitude (V)	4.91[2] (4.87 - 4.98[3])
Characteristics
Spectral type	O9.7Iab[4]
Apparent magnitude (U)	4.05[5]
Apparent magnitude (B)	4.99[5]
Apparent magnitude (J)	4.74[5]
Apparent magnitude (H)	4.679[6]
Apparent magnitude (K)	4.612[6]
U−B color index	−0.84[5]
B−V color index	+0.05[5]
Variable type	Suspected α Cygni[3]
Astrometry
Radial velocity (Rv)	+6.30[7] km/s
Proper motion (μ)	RA: +0.865[1] mas/yr Dec.: −2.985[1] mas/yr
Parallax (π)	1.0967±0.1007 mas[1]
Distance	3,260 ly (1,000[8] pc)
Absolute magnitude (MV)	−6.45[2]
Details[9]
Mass	33.3[10] M☉
Radius	25[2] R☉
Luminosity (bolometric)	339,000[2] L☉
Surface gravity (log g)	2.90[2] cgs
Temperature	28,000[2] K
Rotational velocity (v sin i)	57[2] km/s
Age	4.7[10] Myr
Other designations
Mu Normae, HD 149038, HR 6155, HIP 81122, CD−43°10900
Database references
SIMBAD	data

It shines as bright as 339,000 Suns and weighs 40 solar masses. It varies in visual magnitude between 4.87 and 4.98, and is suspected of being an Alpha Cygni variable, which are named after Deneb.

It is in the same direction and at the same distance as the faint open cluster NGC 6169, although it is brighter than the combined magnitude of all the other stars in the cluster. It was considered the prototype of the μ Normae class of open clusters by Collinder.^[12]