Theta2 Microscopii

For other stars with the name θ Microscopii, see Theta Microscopii.

Theta² Microscopii (θ² Mic) is a class A0III^[3] (white giant) star in the constellation Microscopium. Its apparent magnitude is 5.76^[2] and it is approximately 390 light years away based on parallax.^[1] It is an Ap star, a chemically peculiar star with unusually strong metallic spectral lines.^[9]

θ² Microscopii

Location of θ2 Microscopii (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Microscopium
Right ascension	21h 24m 24.81796s[1]
Declination	−41° 00′ 24.1033″[1]
Apparent magnitude (V)	5.76[2]
Characteristics
Spectral type	A0IIIpSi[3]
U−B color index	-0.21[4]
B−V color index	-0.04[5]
Astrometry
Radial velocity (Rv)	+8.00[6] km/s
Proper motion (μ)	RA: +24.64[1] mas/yr Dec.: −0.25[1] mas/yr
Parallax (π)	8.35±0.70 mas[1]
Distance	390 ± 30 ly (120 ± 10 pc)
Absolute magnitude (MV)	0.39[2]
Orbit[7]
Period (P)	464.66 yr
Semi-major axis (a)	0.836″
Eccentricity (e)	0.210
Inclination (i)	111.8°
Details
Luminosity	78.22[2] L☉
Temperature	10,378[8] K
Other designations
CD−41 14503, CCDM J21245-4100AB, GC 29950, HIP 105696, HR 8180, HD 203585, SAO 230667, WDS J21244-4100AB
Database references
SIMBAD	data

The main star is known to be a binary, with two components A (6.24 mag) and B (6.88 mag) orbiting with a semimajor axis of 0.836" and eccentricity 0.201, with a period 464.66 years.^[10] A more distant companion, C, has a separation around 78.4" and magnitude 10.3.^[11]