Iota Microscopii

ι Microscopii, Latinized as Iota Microscopii, is a suspected astrometric binary^[10] star system in the southern constellation of Microscopium, near the southern constellation border with Indus. It is visible to the naked eye as a dim, yellow-white hued point of light with an apparent visual magnitude of 5.11.^[2] This object is 121 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −14 km/s.^[1]

ι Microscopii

Location of ι Microscopii (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Microscopium
Right ascension	20h 48m 29.14779s[1]
Declination	−43° 59′ 18.6369″[1]
Apparent magnitude (V)	5.11[2]
Characteristics
Spectral type	F2V[3]
U−B color index	+0.04[4]
B−V color index	+0.35[5]
Astrometry
Radial velocity (Rv)	−14.35±0.69 km/s
Proper motion (μ)	RA: +178.881[1] mas/yr Dec.: −112.407[1] mas/yr
Parallax (π)	26.9052±0.1782 mas[1]
Distance	121.2 ± 0.8 ly (37.2 ± 0.2 pc)
Absolute magnitude (MV)	2.05[2]
Details
Mass	1.42[6] M☉
Radius	2.4[7] R☉
Luminosity	12.65[2] L☉
Surface gravity (log g)	3.90±0.14[6] cgs
Temperature	6,997±238[6] K
Metallicity [Fe/H]	−0.03[2] dex
Rotational velocity (v sin i)	115[8] km/s
Age	1.094[6] Gyr
Other designations
ι Mic, CD−44°14145, FK5 1542, GC 28980, GJ 808.1, GJ 9708, HD 197937, HIP 102693, HR 7943, SAO 230379, CCDM J20485-4359A, WDS J20485-4359A[9]
Database references
SIMBAD	data

The visible component is an ordinary F-type main-sequence star with a stellar classification of F2V,^[3] which indicates it is generating energy through core hydrogen fusion. It is around a billion years old with 1.4 times the mass of the Sun^[6] and 2.4^[7] times the Sun's radius. The star is radiating 13^[2] times the luminosity of the Sun from its photosphere at an effective temperature of 6,997 K.^[6] It has a high rate of spin with a projected rotational velocity of 115 km/s, which is giving the star an equatorial bulge that is 6% larger than the polar radius.^[8]

Iota Microscopii has one visual companion, first observed in 1932, with a separation of 4.3" and a visual magnitude of 15.5.^[11]