R Leporis (R Lep), sometimes called Hind's Crimson Star, is a well-known

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...

in the constellation Lepus, near its border with Eridanus. It is designated "R" in the chart to the right. RLeporis

It is a

carbon star A carbon star (C-type star) is typically an asymptotic giant branch star, a luminous red giant, whose atmosphere contains more carbon than oxygen. The two elements combine in the upper layers of the star, forming carbon monoxide, which consumes mo ...

which appears distinctly red. It is named after famous British astronomer J. R. Hind, who observed it in 1845. Its

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

varies from +5.5 to +11.7 with a period of 418–441 days; recent measurements give a period of 427.07 days. There may be a secondary period of 40 years. R Leporis is too far from earth for its parallax to be measured effectively; Guandalini and Cristallo calculated the luminosity of Mira variables based on their periods. Using a period of 427.07 days, they calculated the bolometric luminosity to be . It was estimated to around 1,350 light-years distant in a 2012 paper, shining with a

luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a s ...

approximately 6,689 times that of the Sun and has a surface temperature of 2,980 K. RLepLightCurve

R Leporis has often been reported as an intense smoky red color, although this is not pronounced when the star is near its maximum brightness. It is reddest when it is dimmest, which occurs every 14.5 months. During these periods it is a candidate for the most-visible reddest star, but this claim is questionable. The red coloration may be caused by carbon in the star's outer atmosphere filtering out the blue part of its visible light spectrum. The star's discoverer, Hind, reported that it appeared "like a drop of blood on a black field."

References

External links

Best of the Advanced Observation Program: R Leporis

Smoky Mountain Astronomical Society - Hind's Crimson Star: R Leporis

Geody Hinds Crimson Star

Observations of R LEP from AAVSO

{{DEFAULTSORT:R Leporis Carbon stars Mira variables Lepus (constellation) 031996 023203 Leporis, R 1607 Emission-line stars Durchmusterung objects TIC objects