T Microscopii

T Microscopii is a semiregular variable star in the constellation Microscopium. It ranges from magnitude 6.74 to 8.11 over a period of 352 days.^[3] Located around 700 light-years distant, it shines with a bolometric luminosity 7,509 times that of the Sun and has a surface temperature of 2,750 K.^[5]

T Microscopii

A visual band light curve of T Microscopii, plotted from ASAS data[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Microscopium
Right ascension	20h 27m 55.18840s[2]
Declination	−28° 15′ 39.8035″[2]
Apparent magnitude (V)	6.74 - 8.11[3]
Characteristics
Spectral type	M6-M8IIIe[3]
Variable type	SRb[3]
Astrometry
Proper motion (μ)	RA: −4.682±0.594[4] mas/yr Dec.: 12.562±0.433[4] mas/yr
Parallax (π)	5.1811±0.3864 mas[4]
Distance	630 ± 50 ly (190 ± 10 pc)
Details
Radius	382[5] R☉
Luminosity	7,509[5] L☉
Surface gravity (log g)	−0.427[5] cgs
Temperature	2,750[5] K
Other designations
T Microscopii, HIP 100935, HD 194676, SAO 189308, CD−28°16682
Database references
SIMBAD	data

In 1896 it was announced that Williamina Fleming had discovered that the star is a variable star, based on photographs taken from 1888 through 1895.^[6] It was listed with its variable star designation, T Microscopii, in Annie Jump Cannon's 1907 work Second Catalog of Variable Stars.^[7]