R Fornacis is a Mira variable and carbon star located in the constellation Fornax. It is around 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 dredge-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.[
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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.[ In 1983, an unusually deep minimum was observed, and later correlated with an asymmetric shell of material ejected from the surface of the star.][ Unconfirmed visual estimates of the unusual minimum give a magnitude of 14.0, while infrared observations confirm the unusual variation.][
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Possible planetary system
A study led by C. Paladini, using near-infrared interferometry at the Very Large Telescope, detected a photocenter shift between R Fornacis and an object on its circumstellar envelope. This might be caused by a dust blob that moves around the circumstellar dust, or by a Jupiter-mass companion (), with an orbital period around R Fornacis of 185 years.[
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