R Fornacis

R Fornacis

The visual band light curve of R Fornacis, from AAVSO data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Fornax
Right ascension 02h 29m 15.308s[2]
Declination −26° 05′ 55.65″[2]
Apparent magnitude (V) 7.5 - 13.0[3]
Characteristics
Evolutionary stage AGB[4]
Spectral type C4,3e[5]
Apparent magnitude (J) 3.82[6]
Apparent magnitude (K) 1.06[6]
Variable type Mira[3]
Astrometry
Proper motion (μ) RA: 8.551[2] mas/yr
Dec.: −3.957[2] mas/yr
Parallax (π)1.8069 ± 0.0358 mas[2]
Distance1,810 ± 40 ly
(550 ± 10 pc)
Details
Mass1.05[7] M
Radius575[8][a] R
Luminosity5,800[8] L
Surface gravity (log g)0.12[7] cgs
Temperature2,100[8] K
Metallicity [Fe/H]0.21[7] dex
Other designations
R For, CD−26°892, IRAS 02270-2619, 2MASS J02291531-2605559
Database references
SIMBADdata

R Fornacis is a Mira variable and carbon star located in the constellation Fornax. It is around 1,800 light years away based on parallax measurements.

R Fornacis is a carbon star, a star on the asymptotic giant branch with an excess of carbon over oxygen in its atmosphere due to fusion products being dredged up to the surface from deep inside the star. It is also a Mira variable, a type of pulsating giant star which varies by several apparent magnitudes with a period of a few hundred days. R Fornacis has a period of 389 days and varies between extremes of magnitude 7.5 and 13.0, although average maximum and minimum magnitudes are 8.9 and 12.2 respectively.[9]

R Fornacis was discovered to be variable in 1896 after it had been observed with a different brightness to that shown in the Cordoba Durchmusterung.[10] In 1983, an unusually deep minimum was observed, and later correlated with an asymmetric shell of material ejected from the surface of the star.[4] Unconfirmed visual estimates of the unusual minimum give a magnitude of 14.0, while infrared observations confirm the unusual variation.[9]

  1. ^ Cite error: The named reference aavso was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference edr3 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference paladini2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference yamashita1975 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference ubv was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference starhorse was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference dust_agb was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference feast1984 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference pickering1896 was invoked but never defined (see the help page).


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