Alpha Centauri is a triple star system consisting of Alpha Centauri A and B, and the closest star to our Sun, Proxima Centauri (Alpha Centauri C) at 4.2 light years away. Proxima Centauri is a red dwarf star, only visible through large telescopes, and revolves around the other two stars once every 550,000 years. Two planets have been confirmed in orbit around Proxima: Proxima b and Proxima c. Proxima b is an Earth-mass planet discovered in 2016, which is located within the habitable zone of Proxima Centauri, while Proxima c is a super-Earth exoplanet discovered in 2020, which orbits the star once every 1928 days.
Carina Nebula (NGC 3372) is more than four times larger than the more famous Orion Nebula (M42) seen in summer. Its distance of around 7500 light years disguises its immense size of around 500 light years in diameter. On a moonless night it is a stunning view through binoculars or a telescope as well as being visible to the naked eye. It contains some of the youngest star clusters in the Milky Way as well as a star already coming to an explosive death. The star Eta Carinae is 100-150 times the mass of the Sun and is a dying cataclysmic variable, which is expected to explode as a supernova anytime within the next million years. A supernova precursor eruption in the 1840s temporarily elevated it to the second brightest star in the night sky.
NGC 3293 and NGC 3532 are two stunning open clusters in Carina and both excellent targets for binocular and telescope viewing. NGC 3532 was the first target of the Hubble Space Telescope in 1990. It contains around 150 stars thought to be 300 million years old at a distance of 1300 light years. NGC 3293 is much younger with stars between 6 and 20 million years but around 9000 light years away.
The Jewel Box (NGC 4755) is an open star cluster approximately 10 million years old. It is close to Beta Crucis (Mimosa), the second-brightest star in Crux (Southern Cross) and in binoculars and small telescopes appears as an ‘A’ shape. It is about 20 light years across, and has around 100 stars, most of which are blue and include some blue and red super giants such as DU Crucis which is around 500 times the diameter of the Sun. The Jewel Box is one of the youngest open clusters in our skies with an estimated age of about 14 million years. It lies at a distance of about 6400 light years.
M4 is the closest globular cluster to Earth at 5500 light years away. M4 is easy to locate, sitting next to the red supergiant star, Antares, in Scorpius. The cluster contains more than 100,000 stars with approximately 40,000 of these being white dwarf stars.
M6 the Butterfly and M7 Ptolemy’s are two open star clusters found near the sting of the Scorpion. M6 is about 1600 light years away and M7 is about 980 light years.
Omega Centauri (NGC 5139) is the brightest and largest of approximately 150 globular clusters orbiting the Milky Way. It is so bright it was labelled as a star on early sky charts by Ptolemy and is one of the few objects in the sky that carries both a star designation and an object catalogue designation. Omega Centauri shines with the luminosity of a million suns and is relatively close to us, only 15,800 light years away. It contains approximately 10 million stars and some theories suggest it could be the remnant core of a galaxy that is merging with the Milky Way.
The Sombrero Galaxy (M104 or NGC 4594) is an almost edge on barred spiral galaxy about 30% the size of the Milky Way, 28 million light years away. Its central black hole is about one billion times the mass of our Sun, which makes it one of the largest black holes found so far in the heart of a galaxy. The Sombrero Galaxy is situated within the constellation Virgo on the border with Corvus. It requires a moderate sized telescope and will appear as a small smoky smudge.
