Rho Coronae Borealis is a yellow dwarf star considered to be a solar twin: a star with roughly equal mass, luminosity and radius to the Sun. In 1997, scientists confirmed an extrasolar planet orbiting the star.
Rho Coronae Borealis lies 57 light-years from Earth, in the small northern constellation Corona Borealis.
Rho Coronae Borealis
Photo: Marhorr
Eta Carinae Nebula (NGC 3372) in Carina constellation is a large emission nebula that contains a number of O-type stars and several open star clusters. The brightest, most notable star in the nebula is eta Carinae, a supergiant 100 times as massive as the Sun, expected to explode as a supernova or hypernova in the relatively near future. Eta Carinae is one of the brightest and most massive stars in the Milky Way galaxy. It lies 7,500 – 8,000 light-years away.
The Carina Nebula is between 6,500 and 10,000 light-years distant from Earth.
Eta Carinae Nebula in Carina constellation
Photo: Spitzer Science Center
Sirius is the brightest star in the night sky. It is located in the constellation Canis Major. Sirius is really a binary system consisting of Sirius A, a white main sequence star, and Sirius B, a white dwarf. It is only 8.6 light-years distant from Earth.
Sirius has an apparent visual magnitude of -1.46 and the only brighter objects in the sky lie inside our own solar system.
Together with the stars Rigel in Orion, Aldebaran in Taurus, Capella in Auriga, Pollux and Castor in Gemini and Procyon in Canis Minor, Sirius forms the Winter Hexagon, an asterism in the night sky that can be spotted from December to March.
Sirius A and Sirius B in Canis Major
Photo: NASA/ESA (Hubble)
Gamma Caeli is an interesting multiple star system in the Caelum constellation. It actually consists of two star systems. The brighter one, gamma-1 Caeli is a binary star with an orange giant for a primary component and a fainter star as the companion. Gamma-2 Caeli, another double star system, consists of a yellow-white giant and also a fainter companion star.
Gamma Caeli in Caelum
Photo: Wikisky.org
The star map below shows how to find Arcturus in the night sky by following the stars of Ursa Major‘s tail.
Arcturus, also known as alpha Bootis, is an orange giant in the Bootes constellation, about 37 light-years distant. It is the third brightest star in the sky, after Sirius in the constellation Canis Major and Canopus in Carina.
How to find Arcturus in the night sky
Picture: Jim Thomas
