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]
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 | |
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]