Betelgeuse, as seen by the Hubble Space Telescope, and in relation to the Orion constellation. Also known as Alpha Orionis, it is nevertheless easy to spot in the Orion constellation since it is one of the largest and most luminous stars in the night sky. Pronounced вЂњBeetle-juiceвЂќ (yes, the same as the 1988 Tim Burton movie), this bright red supergiant is roughly 65o light-year from Earth. Known as Alpha Centauri Bb, itвЂ™s close proximity to its parent star likely means that it is too hot to support life. In 2012, astronomers discovered an Earth-sized planet around Alpha Centauri B. Proxima Centauri was discovered in 1915 by Scottish astronomer Robert Innes, Director of the Union Observatory in Johannesburg, South Africa. In 1689, Jesuit priest and astronomer Jean Richaud confirmed the existence of a second star in the system. Proxima Centauri, the smallest of the three, is a red dwarf roughly 0.12 times the mass of our Sun, and which is the closest of the three to our Solar System.Д®nglish explorer Robert Hues was the first European to make a recorded mention of Alpha Centauri, which he did in his 1592 work Tractatus de Globis. Alpha Centauri B is an orange subgiant with 90.7% of the SunвЂ™s mass and 44.5% of its luminosity. Credit: ESOД«ased on their spectral classifications, Alpha Centauri A is a main sequence white dwarf with roughly 110% of the mass and 151.9% the luminosity of our Sun. ArtistвЂ™s impression of the planet around Alpha Centauri B. But much like Sirius and Polaris, it is actually a multistar system, consisting of Alpha Centauri A, B, and Proxima Centauri (aka. It is also the closest star system to Earth, at just a shade over four light-years. To the Polynesians in the southern hemisphere, it marked the approach of winter and was an important star for navigation around the Pacific Ocean.ДЄlso known as Rigel Kent or Toliman, Alpha Centauri is the brightest star in the southern constellation of Centaurus and the third brightest star in the night sky. For the Greeks, the rising of Sirius in the night sky was a sign of theвЂќdog days of summerвЂќ. In ancient Egypt, it was seen as a signal that the flooding of the Nile was close at hand. For the next 60,000 years or so, astronomers expect that it will continue to approach our Solar System at which point, it will begin to recede again. And in truth, it is actually getting closer. The reason why it is so bright in the sky is due to a combination of its luminosity and distance вЂ“ at 6.8 light years, it is one of EarthвЂ™s nearest neighbors. Whereas it appears to be a single bright star to the naked eye, Sirius is actually a binary star system, consisting of a white main-sequence star named Sirius A, and a faint white dwarf companion named Sirius B. The name вЂњSiriusвЂќ is derived from the Ancient Greek вЂњSeirios вЂњ, which translates to вЂњglowingвЂќ or вЂњscorcherвЂќ.

Credit: Bob KingДЄlso known as the Dog Star, because itвЂ™s the brightest star in Canis Major (the вЂњBig DogвЂќ), Sirius is also the brightest star in the night sky.

Stars at the edge of the frame make much larger circles. Notice that the closer stars are to Polaris, the smaller the circles they describe. Time exposure centered on Polaris, the North Star. Many scientific papers suggest that it may be up to 30% closer to our Solar System than previously expected вЂ“ putting it in the vicinity of 238 light years away. a star that pulsates radially, varying in both temperature and diameter to produce brightness changes вЂ“ itвЂ™s distance to our Sun has been the subject of revision. But until such time as EarthвЂ™s axis moves farther away from the вЂњPolestarвЂќ, it remains our guide.Д«ecause it is what is known as a Cepheid variable star вЂ“ i.e. ThatвЂ™s because EarthвЂ™s axis wobbles over thousands of years and points in different directions. Interestingly enough, Polaris wasnвЂ™t always the north star. These, along with its two distant components (alpha UMi C, alpha UMi D), make it a multistar system. WhatвЂ™s more, rather than being a single supergiant, Polaris is actually a trinary star system, comprised of a main star (alpha UMi Aa) and two smaller companions (alpha UMi B, alpha UMi Ab). ItвЂ™s more than 430 light-years away from Earth, but its luminosity (being a white supergiant) makes it highly visible to us here on Earth. The Polaris star system, as seen within the Ursa Minor constellation and up close.

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