U Antliae

U Antliae
Location of U Antliae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Antlia
Right ascension 10h 35m 12.852s[1]
Declination −39° 33′ 45.32″[1]
Apparent magnitude (V) 5.27 - 6.04[2]
Characteristics
Evolutionary stage AGB
Spectral type C-N3[3] (C5,3[4])
U−B color index 7.10[5]
B−V color index 2.84[5]
Variable type LB[6]
Astrometry
Radial velocity (Rv)41.00[7] km/s
Proper motion (μ) RA: −31.372±0.228[8] mas/yr
Dec.: 2.371±0.267[8] mas/yr
Parallax (π)3.5717 ± 0.2043 mas[8]
Distance910 ± 50 ly
(280 ± 20 pc)
Absolute magnitude (MV)−1.87[9]
Details
Radius422[10][a] R☉
Luminosity4,500[10] L☉
Temperature2,300[10] K
Other designations
HR 4153, HD 91793, HIP 51821, CD−38°6579, 2MASS J10351285-3933453, PPM 287864, AAVSO 1030–39, SAO 201533
Database references
SIMBADdata
ALMA image of the dust shells around U Antliae

U Antliae (U Ant) is a variable star in the constellation Antlia. It is a carbon star surrounded by two thin shells of dust.

U Antliae is an extremely red C-type carbon star. These cool stars on the asymptotic giant branch are further reddened by strong mass loss and dust that forms around the star. U Antliae is calculated to have an effective surface temperature of 2,800 K, although the light that reaches us has an appearance more like that from a black body with a temperature of 2,300 K surrounded by dust at a temperature of 72 K.[11] It emits most of its radiation in the infrared and although it is only about 500 times brighter than the sun at visual wavelengths,[9] its bolometric luminosity is 8,000 times higher than the Sun's.[11]

The visual band light curve of T Antliae, from AAVSO data[12]

In 1901, Louisa Dennison Wells discovered that the brightness of the star varied, from the examination of photographic plates.[13] Annie Jump Cannon included the star, with its variable star designation U Antiliae, in her 1907 Second Catalogue of Variable Stars.[14] U Antliae is an irregular variable star with an apparent magnitude that varies between 5.27 and 6.04. Approximately 900 light years from Earth, it is surrounded by two shells of dust, thought to have been ejected 14,000 and 10,000 years ago.[15] The exact origin and structure of the shells is uncertain, possibly due to enhanced mass loss during thermal pulses, possibly due to interaction of the stellar wind with interstellar material.[11]

  1. ^ a b Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference AAVSOU was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference demello was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference yamashita was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference ducati was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference rv was invoked but never defined (see the help page).
  8. ^ a b c 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.
  9. ^ a b Cite error: The named reference alksnis was invoked but never defined (see the help page).
  10. ^ a b c Răstău, V.; Mečina, M.; Kerschbaum, F.; Olofsson, H.; Maercker, M.; Drechsler, M.; Strottner, X.; Mulato, L. (2023-12-01), "Extended far-UV emission surrounding asymptotic giant branch stars as seen by GALEX", Astronomy & Astrophysics, 680: A12, arXiv:2310.09056, doi:10.1051/0004-6361/202346120, ISSN 0004-6361
  11. ^ a b c Cite error: The named reference kerschbaum was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference aavso was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Pickering was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Cannon was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Izumiura was invoked but never defined (see the help page).


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