LP Andromedae

LP Andromedae

A near-infrared (L band) light curve for LP Andromedae, adapted from Jones et al. (1990)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 34m 27.5216s[2]
Declination +43° 33′ 01.2996″[2]
Apparent magnitude (V) 15.12 variable[3]
Characteristics
Spectral type C8,3.5e[4]
Apparent magnitude (G) 16.9041[2]
Apparent magnitude (J) 9.623[5]
Apparent magnitude (H) 6.355[5]
Apparent magnitude (K) 2.71[6]
Variable type Mira[7]
Astrometry
Proper motion (μ) RA: −21.313±0.532 [2] mas/yr
Dec.: −22.058±0.453[2] mas/yr
Parallax (π)2.5002 ± 0.3626 mas[2]
Distanceapprox. 1,300 ly
(approx. 400 pc)
Absolute bolometric
magnitude (Mbol)		−5.21±0.26[8]
Details[8]
Mass0.8 M☉
Radius340 – 420 R☉
Luminosity2,900 – 16,200 L☉
Temperature2,100 – 3,350 K
Other designations
2MASS J23342752+4333012, IRAS 23320+4316, RAFGL 3116
Database references
SIMBADdata

LP Andromedae (often abbreviated to LP And) is a carbon star in the constellation Andromeda. It is also a Mira variable[7] whose mean apparent visual magnitude is 15.12 and has pulsations with an amplitude of 1.50 magnitudes[3] and a period of 614 days.[8]

In 1974 LP Andromedae, known then as IRC+40540, was identified as a carbon star and also shown to be variable.[9] It had previously been suspected of variability during the 2 Micron All Sky Survey (2MASS). A detailed study of its spectrum showed an unusually cool star with a basic class of C8, and Swan band strength of 3.5. It also showed strong C13 isotopic bands.[4] The period was narrowed down to around 614 days, one of the longest periods known for a Mira variable.[10]

This star has a dusty envelope with an estimated mass of 3.2 M☉, fueled by the star itself which is losing mass at a rate 1.9×10−5 M☉/yr. Such a high mass loss rate should place LP Andromedae close to the end of its asymptotic giant branch evolution. The envelope extends to a distance of 3 parsec from the star, and is mainly made of silicon carbide and carbon particles.[8]

  1. ^ Cite error: The named reference Jones was invoked but never defined (see the help page).
  2. ^ a b c d e f 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.
  3. ^ a b Cite error: The named reference Catalina was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference cohen was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference 2MASS Cat was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Menzies2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference GCVS was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference aaa_1_448 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference lockwood was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference alksnis was invoked but never defined (see the help page).