Lepus is a constellation lying just south of the celestial equator. Its name is Latin for hare. It is located below—immediately south—of Orion (the hunter), and is represented as a hare being chased by Orion’s hunting dogs. Lepus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. Lepus is the 51st constellation in size, occupying an area of 290 square degrees. It is located in the second quadrant of the northern hemisphere and can be seen at latitudes between +63° and -90°. The neighbouring constellations are Caelum, Canis Major, Columba, Eridanus, Monoceros and Orion. Lepus belongs to the Orion family of constellations, along with Canis Major, Canis Minor, Monoceros and Orion. This constellation should not be confused with Lupus, the wolf.
There are a fair number of bright stars, both single and double, in Lepus. Alpha Leporis, the brightest star of Lepus, is a white supergiant of magnitude 2.6, 1300 light-years from Earth. Its traditional name, Arneb, means “hare.” Beta Leporis, called Nihal, is a yellow giant of magnitude 2.8, 159 light-years from Earth. Gamma Leporis is a double star divisible in binoculars. The primary is a yellow star of magnitude 3.6, 29 light-years from Earth. The secondary is an orange star of magnitude 6.2. Delta Leporis is a yellow giant of magnitude 3.8, 112 light-years from Earth. Epsilon Leporis is an orange giant of magnitude 3.2, 227 light-years from Earth. Kappa Leporis is a double star, 560 light-years from Earth. The primary is a blue-white star of magnitude 4.4 and the secondary is a star of magnitude 7.4. There are several variable stars in Lepus. R Leporis is a Mira variable star. It is also called “Hind’s Crimson Star” for its striking red colour and because it was named for John Russell Hind. It varies in magnitude from a minimum of 9.8 to a maximum of 7.3, with a period of 420 days. R Leporis is at a distance of 1500 light-years. The colour intensifies as the star brightens. It can be as dim as magnitude 12 and as bright as magnitude 5.5. T Leporis is also a Mira variable observed in detail by ESO’s Very Large Telescope Interferometer. RX Leporis is a semi-regular red giant that has a period of 2 months. It has a minimum magnitude of 7.4 and a maximum magnitude of 5.0.
There is one Messier object in Lepus, M79. It is a globular cluster of magnitude 8.0, 42,000 light-years from Earth. One of the few globular clusters visible in the Northern Celestial Hemisphere’s winter, it is a Shapley class V cluster, which means that it has an intermediate concentration towards its centre. It is often described as having a “starfish” shape. M79 was discovered in 1780 by Pierre Méchain. IC 418 is a planetary nebula in Lepus. It was named the Spirograph Nebula because it has an intricate pattern, similar to those that can be created with a spirograph. The nebula has an apparent magnitude of 9.6 and is approximately 1,100 light years distant from the solar system. NGC 1821 is type IB(s)m irregular galaxy in Lepus. It has an apparent magnitude of 14.5. The galaxy was discovered by the American astronomer Frank Leavenworth in 1886. A supernova, SN 2002bj, was observed in the galaxy in 2002. At first, it had an apparent magnitude of 14.7 and was classified as a Type IIn supernova, but in 2008, it was determined that the spectrum resembled that of a Type Ia supernova more closely. The progenitor star system is believed to have been composed of two white dwarfs, with helium being transferred from one to the other. Once the helium accreted, it exploded in a thermonuclear reaction on the surface of the more massive star, which resulted in the outburst. Credit: Wikipedia.