Magnitude 7.71 | ||
Similar Chi Cygni, Mira, R Hydrae, U Orionis, R Doradus | ||
R Leonis is a red giant Mira-type variable star in the constellation Leo.
The apparent magnitude of R Leonis varies between 4.31 and 11.65 with a period of 312 days. At maximum it can be seen with the naked eye, while at minimum a telescope of at least 7 cm is needed. The star's effective temperature is estimated between 2,930 and 3,080 kelvins and radius spans between 320 and 350 solar radii (as large as 1.36–1.5 astronomical units, roughly Mars's orbital zone).
A planetary system?
In 2009 Wiesemeyer et al. proposed that quasi-periodic fluctuations observed for the star R Leonis may be due to the presence of an evaporating substellar companion, probably an extrasolar planet. They have inferred a putative mass for the orbiting body of twice the mass of Jupiter, orbital period of 5.2 years and likely orbital separation of 2.7–3 astronomical units. If confirmed such a planetary object could likely be an evaporating planet, with long comet-like trail as hinted by intense SiO maser emissions. Planetary temperature would exceed 1,500 kelvins, accounting a stellar luminosity of more than 8,000 times that of the Sun.