Lepus has one star with known planets and two formally named stars. The star names, as approved by the International Astronomical Union (IAU) are Arneb and Nihal. There is one Messier object in Lepus, Messier 79, and the brightest star in the constellation is Arneb, with an apparent magnitude of 2.58. The constellation is also home to the famous variable star known as Hind’s Crimson Star, the irregular galaxy NGC 1821 and the Spirograph Nebula (IC 418).
History and Mythology of the Lepus Constellation
Lepus is not associated with any figure in Greek mythology, but is often represented as a hare being hunted by Orion, whose hunting dogs, Canis Major and Canis Minor, pursue it. The constellation is also associated with the Moon rabbit, which is a mythical figure who lives on the Moon in Far Eastern folklore.
Location of the Lepus Constellation
Lepus constellation is the 51st largest constellation in size and occupies an area of 290 square degrees. It is located in the second quadrant of the northern hemisphere (NQ2) and can be seen at latitudes between +63° and -90°.
Its right ascension is 6h and its declination is −20°. It is best seen at 9pm during the month of January. Lepus’ neighboring constellations are Caelum, Canis Major, Columba, Eridanus, Monoceros and Orion, and it belongs to the Orion family of constellations, along with Canis Major, Canis Minor, Monoceros and Orion.
Arneb, also known as Alpha Leporis, is the brightest star in Lepus and has an apparent magnitude of 2.589. It is a lower luminosity yellow-white supergiant star with the stellar classification F0 Ib. It is known to be an old, dying star, about 13 million years old, which is either still expanding or has passed through the supergiant stage. Arneb, it is believed, will end its life in a supernova explosion.
Arneb is located around 2,200 light years away from the Solar System and is 32,000 times more luminous than the Sun. It also has a mass that is around 14 times that of the Sun and a radius that is 129 times that of the Sun. Its name Arneb comes from the Arabic arnab, which means “the hare”.
Nihal, also known as Beta Leporis, is a yellow bright giant with the stellar classification G5 II. It is a double star system and possibly a binary star, composed of two stars with an apparent magnitude of 2.84. They are thought to be separated by 2.58 arc seconds.
Nihal is located around 160 light years away from the Sun and is thought to be about 240 million years old. It has a mass that is 3.5 times that of the Sun and a radius that is 16 times that of the Sun. The name Nihal means “quenching their thirst”.
Epsilon Leporis is an orange giant star with the stellar classification K4 III and an apparent magnitude of 3.166. It is 372 times more luminous than the Sun and thought to be around 1.72 billion years old.
It is located 213 light years away from us and has a mass that is 1.70 times that of the Sun. Its radius is 40 times that of the Sun.
Mu Leporis is a blue-white subgiant star with the stellar classification of B9 IV:HgMn and an apparent magnitude of 3.259. It is a suspected variable star of the Alpha-2 Canum Venaticorum type, with a period of about two days. It is located around 186 light years away form the Solar System.
Zeta Leporis is a white main sequence star which is evolving into a subgiant, with the stellar classification of A2 IV-V(n). The (n) indicates that the absorption lines in the star’s spectrum look nebulous because the star is a rapid spinner. This causes the absorption lines to broaden as a result of the Doppler shift.
Zeta Leporis is located around 70.5 light years away from the Solar System and has an apparent magnitude of 3.524. Its mass is 1.46 times that of the Sun and its radius is 1.5 times that of the Sun. The star is thought to be around 231 million years old and is 14 times more luminous than the Sun.
Delta Leporis is an orange subgiant star with the stellar classification K1IVFe-0.5 and an apparent magnitude of 3.81. It is located around 114 light years away from the Solar System.
Gamma Leporis is a yellow-white main sequence star with the stellar classification F6V and an apparent magnitude of 3.59. It is a member of the Ursa Major Moving Group and a high-priority target for the Terrestrial Planet Finder mission.
It is located around 29.3 light years away from us and has a mass that is 1.3 times that of the Sun and a radius which is 1.2 times that of the Sun.
Eta Leporis is a yellow-white dwarf with the stellar classification of F2V and an apparent magnitude of 3.719. It has a mass that is 1.42 times that of the Sun and a radius that is 1.5 times that of the Sun. It is located 49.1 light years away from the Sun. In recent years, excess infrared emission has been detected coming from the star, indicating that it has a dust disk.
RX Leporis is a red giant with the stellar classification M6.2III. It is a semi-regular pulsating star with an apparent magnitude that varies between 5 and 7.4. RX Leporis is located next to Iota Leporis, four degrees south of the bright star Rigel, and is approximately 490 light years distant from Earth.
17 Leporis, also known as SS Leporis, is a spectroscopic binary star with components belonging to the spectral classes A1 and M3-4.5. They have a period of 260.34 days and a visual magnitude that varies between 4.82 and 5.06. The star is located around 1,100 light years away from the Solar System.
Hind’s Crimson Star
Hind’s Crimson Star, also known as R Leporis, is a carbon star with the stellar classification of C7,6e(N6e), and classified as a long-period Mira variable with a period of 418-441 days, and a secondary period of about 40 years. It is also a variable with its magnitude ranging from 5.5 to 11.7. It is between 5,200 and 7,000 times more luminous than the Sun and its radius is 500 times that of the Sun.
Hind’s Crimson Star is located around 1,300 light years away from us and near the border with Eridanus constellation. It is very red and got its name as the “crimson star” as the British astronomer J. R. Hind, who discovered it in 1845, described it as appearing “like a drop of blood on a black field”.
Gliese 229 is a red dwarf that belongs to the spectral class M1Ve. It has a mass that is 58% that of the Sun’s and a radius that is 69% of the Sun’s. It is also a low activity flare star, with magnetic activity on its surface causing random increases in brightness. Gliese 229 is located around 18.8 light years away from the Sun and is a slow rotator.
In 1994, a substellar companion, a brown dwarf of the spectral type T7, was discovered orbiting the star.
T Leporis is a red giant star belonging to the stellar class M6II with an apparent magnitude of 9.94. It is a Mira variable and pulsates with a period of 380 days. With each pulsation, it loses approximately the mass of Earth.
T Leporis has a mass 100 times that of the Sun and is located around 500 light years away from us.
Throne of Jawza
There are four stars that form a quadrilateral asterism in Lepus called Throne of Jawza. These stars are Arneb, Nihal, Gamma Leporis and Delta Leporis. Sometimes, it is also called the Camels, from the Arabic phrase meaning “camels quenching their thirst”.
Deep Sky Objects
Messier 79, also known as M79 or NGC 1904, is a globular cluster that was discovered by the French astronomer Pierre Méchain in 1780 and then included in Charles’ Messier’s catalogue. It has an apparent magnitude of 8.56 and is around 41,000 light years away from Earth.
It is believed to have originated outside the Milky Way, in the Canis Major Dwarf Galaxy, much like Messier 54 in Sagittarius constellation.
Spirograph Nebula, also known as IC 418, is a planetary nebula with an apparent magnitude of 9.6 that is located approximately 1,100 light years away from the Solar System. It is called the Spirograph Nebula because it has an intricate pattern, similar to those that can be created with a spirograph.
NGC 1821 is a type IB(s)m irregular galaxy that was discovered by the American astronomer Frank Leavenworth in 1886. It has an apparent magnitude of 14.5 and is believed to have been composed of two white dwarfs, with helium being transferred from one to the other.
In 2002, a supernova, SN 2002bj, was observed in NGC 1821 with an apparent magnitude of 14.7 and was classified as a Type IIn supernova. However, in 2008, it was determined that the spectrum resembled that of a Type Ia supernova more closely.
- Some Images created with the NightVision app – https://www.nvastro.com/nvj.html
- Some Images created with the Stelvision Sky Map https://www.stelvision.com/en/sky-map/
- Lepus 1 – https://starregistration.net/constellations/lepus-constellation.html
- Arneb – https://theskylive.com/sky/stars/arneb-alpha-leporis-star
- Nihal – https://in-the-sky.org/data/object.php?id=TYC5928-1657-1
- Epsilon Leporis – https://theskylive.com/sky/stars/epsilon-leporis-star
- Gamma Leporis – https://theskylive.com/sky/stars/gamma-leporis-star
- Hind’s Crimson Star – https://apod.nasa.gov/apod/ap181031.html
- Spirograph Nebula – https://apod.nasa.gov/apod/ap100411.html