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
Distance1,100 ± 70 ly
(340 ± 20 pc)
Details
Mass2.7[4] M☉
Surface gravity (log g)−0.5[4] cgs
Temperature2,800[4] K
Other designations
T Lep, BD−22°995, CD−22°995, HD 32803, HIP 23636
Database references
SIMBADdata

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.

See also
  • Mira Ceti

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  3. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
  4. Pérez-Mesa, V.; Zamora, O.; García-Hernández, D. A.; Plez, B.; Manchado, A.; Karakas, A. I.; Lugaro, M. (2017). "Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisited". Astronomy and Astrophysics. 606: A20. arXiv:1706.02268. Bibcode:2017A&A...606A..20P. doi:10.1051/0004-6361/201731245.
  5. Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  6. Nakagawa, Akiharu; Omodaka, Toshihiro; Handa, Toshihiro; Honma, Mareki; Kawaguchi, Noriyuki; Kobayashi, Hideyuki; Oyama, Tomoaki; Sato, Katsuhisa; Shibata, Katsunori M.; Shizugami, Makoto; Tamura, Yoshiaki; Ueno, Yuji (2014). "VLBI astrometry of AGB variables with VERA: A Mira-type variable T Lepus". Publications of the Astronomical Society of Japan. 66 (6): 101. arXiv:1404.4463. Bibcode:2014PASJ...66..101N. doi:10.1093/pasj/psu103.
  7. "Unique Details Of Double Star In Orion Nebula And Star T Leporis Captured By 'Virtual' Telescope". ScienceDaily. 19 February 2009.
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