T Leporis

T Leporis (T Lep / HD 32803 / HIP 23636) is a variable star in the constellation of Lepus, the Hare. It is located half a degree from ε Leporis in the sky; its distance is approximately 1,100 light years from the Solar System. It has the spectral type M6ev, and is a Mira variable — as is R Leporis, in the same constellation — whose apparent magnitude varies between +7.40 and +14.30 with a period of 368.13 days.[2]

T Leporis

T Leporis (below) compared to the Sun and Earth's orbit (above)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Lepus
Right ascension	05h 04m 50.85s[1]
Declination	−21° 54′ 16.5″[1]
Apparent magnitude (V)	7.4 - 14.3[2]
Characteristics
Spectral type	M6e-M9e[2]
Variable type	Mira[2]
Astrometry
Radial velocity (Rv)	−4[3] km/s
Parallax (π)	2.9585 ± 0.1889[1] mas
Distance	1,100 ± 70 ly (340 ± 20 pc)
Details
Mass	2.7[4] M☉
Surface gravity (log g)	−0.5[4] cgs
Temperature	2,800[4] K
Other designations
T Lep, BD−22°995, CD−22°995, HD 32803, HIP 23636
Database references
SIMBAD	data

The annual parallax of T Leporis was measured by the Hipparcos mission, but the results were hopelessly imprecise.[5] The parallax from Gaia Data Release 2 is more accurate and yields a distance of 340±20 pc.[1] The distance has also been measured using very-long-baseline interferometry and found to be 327±4 pc.[6]

Mira variables are some of the major sources of molecules and dust in the Universe. With each pulsation, T Leporis expels matter into space, each year losing an amount equivalent to the mass of Earth. Images of T Leporis obtained with the Very Large Telescope interferometer of the European Southern Observatory (ESO) have revealed a shell of gas and dust surrounding the star, whose diameter is some 100 times larger than that of the Sun.[7] Given the great distance at which this class of stars lie, its apparent angular diameter — despite its enormous size — is no more than a millionth of the solar apparent angular diameter.