T Leporis
Star in the constellation Lepus
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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]
| 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 |
| Proper motion (μ) | RA: +13.59 mas/yr[4] Dec.: −34.55 mas/yr[4] |
| Parallax (π) | 3.06±0.04 mas[4] |
| Distance | 1,066±13 ly (327±4 pc)[4] |
| Details | |
| Mass | 2.7[5] M☉ |
| Radius | 204[4] R☉ |
| Surface gravity (log g) | −0.5[5] cgs |
| Temperature | 2,800[5] 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.[6] 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.[4]
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.[8] 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.