Observation data
Variable star, type Mira (long-period)	C7,6e(N6e)
Right ascension (RA, α) (2000.0)	04 h 59.6 m
Declination (Dec, δ) (2000.0)	-14° 48'
Distance from Earth	1500? LY
Visual brightness (V)	+5.5m to +11.7m
Absolute magnitude
Physical characteristics
Mean Diameter (dS = 1,392,000 km)
Surface area
Volume
Mass
Relative mass to the Sun (mS = 1.9891 × 1030 kg)
Density
Surface gravity
Spectral type	M
Surface temperature
Age
Color (B-V)	+5.5
V-I
Luminosity (LS = 3.827 × 1026 J s-1)
Orbital characteristics
Period of rotation
Period

Hind's Crimson Star, also known as R Leporis, is a well-known variable star, in the constellation Lepus, near the border with Eridanus. It is a carbon star - the carbon is thought to block out the blue light of the star, making it appear red. It is named after famous British astronomer J.R. Hind, who observed it in 1845. Its magnitude varies from 5.5 to 11.7 with a major period of 427 - 432 days, although it may also have other periodic components. Most stars are of nearly constant luminosity. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... To help compare different distances this page lists lengths starting at 109 m (1 million km). ... A kilometre (American spelling: kilometer, symbol: km) is a unit of length equal to 1000 metres (from the Greek words khilia = thousand and metro = count/measure). ... A sun is the star at the center of a solar system. ... (Redirected from 1 E30 kg) Categories: Orders of magnitude (mass) ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... Gravitation is the tendency of masses to move toward each other. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... In physics, luminosity is the density of luminous intensity in a given direction. ... The joule (symbol J, also called newton metre, or coulomb volt) is the SI unit of energy and work. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ... Most stars are of nearly constant luminosity. ... Categories: Astronomy stubs | Constellations listed by Ptolemy | Modern constellations | Constellations | Lepus constellation ... Categories: Astronomy stubs | Constellations listed by Ptolemy | Modern constellations | Constellations ... A carbon star is a red giant (or occasionally red dwarf) star whose atmosphere contains more carbon than oxygen; the two elements combine in the upper layers of the star, forming carbon monoxide and other carbon compounds. ... John Russell Hind (May 12, 1823 – December 23, 1895) was a British astronomer. ... 1845 was a common year starting on Wednesday (see link for calendar). ...

Hind's Crimson Star has often been reported as displaying an intense smoky red color, although this perception is not pronounced when the star is near its maximum brightness. It will be reddest when it is dimmest; it has been said that it is at its reddest only one month in every 14.5 months. At that time, it is a candidate for the reddest star which is easily observable, but this is a disputed assertion.

External links

• Best of the Advanced Observation Program: R Leporis (http://www.noao.edu/outreach/aop/observers/rleporis.html)
• USA Today.com - NightSky: The Hare and the Dove (http://www.usatoday.com/tech/news/2004-01-30-nightsky_x.htm)
• Smoky Mountain Astronomical Society - Hind's Crimson Star: R Leporis (http://www.smokymtnastro.org/scraps/2004/Jan2004.pdf)