constellation corner
constellation corner
Sagittarius ’ offerings are sure to stun
Home to our Milky Way ’ s galactic center , the Sagittarius constellation offers a feast of notable stars , nebulae , clusters and more that can keep your eyepiece filled for nights . Covering an 867 square degree area of sky , the loaded Sagittarius is the 15th largest constellation and is visible from 55 ° North to 90 ° South . Before you delve into the bounty of deep sky treasures , a star tour is always a good way to get acquainted with a constellation . Sagittarius is commonly identified as the “ Archer ,” so it is fitting that the constellation ’ s brightest star – Kaus Australis — anchors the celestial character ’ s bow . Although it will take a larger scope to resolve it , Kaus Australis ( Epsilon Sagittarii ) is a binary star system that has a blue giant with an apparent visual magnitude of 1.79 as its main component . The two other stars that define the bow are Kaus Media ( Delta Sagittarii ), which is a multi-star system made up of a giant and three dim companions , and Kaus Borealis ( Lambda Sagittarii ), an orange giant with an apparent visual magnitude of 2.82 that lies very close to the ecliptic . In addition to rendering the Archer ’ s bow , these three stars are part of the eight that form the constellation ’ s famous Teapot Asterism . Kaus Borealis marks the point of the teapot ’ s lid , while Kaus Australis and Kaus Media define the body of the teapot along with Zeta Sagittarii , a binary star system with a white giant primary , and Phi Sagittarii , a giant with an apparent visual magnitude of 3.17 . At the tip of the teapot ’ s
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COURTESY OF Ray Bureau
The Lagoon Nebula is one of the standout deep sky treats in the Sagittarius Constellation . It covers an area that is about 110 by 50 light years in size and is one of only a few star-forming nebulae that can be seen by the unaided eye . Astrophotographer Ray Bureau used an Explore Scientific ED127 f / 7.5 refractor telescope and an unmodded Canon EOS 70D to get this image .
spout lies Gamma Sagittarii , a binary system with an orange giant that also acts as the tip of the archer ’ s arrow . The two stars that outline the handle of the teapot are Sigma Sagittarii , a fast rotating dwarf that is the second brightest star in the constellation , and the orange giant Tau Sagittarii . About 120 light years away , Tau Sagittarii ’ s fame extends beyond its place in the teapot . It is actually the closest visible star to the origin of the Wow ! Signal , which was the first and only narrowband radio signal ever received that met the criteria for possible communication from an extraterrestrial intelligence source . Detected on August 15th , 1977 , at the Big Ear Radio Observatory in Ohio , the signal lasted for 72 seconds but has not been detected since . It got its name because when he discovered it ,
SETI researcher Jerry Ehman circled the evidence on a computer printout and wrote “ Wow !” next to it in big red letters . Sagittarius is also the home of the Pistol Star , which is one of the most luminous stars known . Obscured to the naked eye by the interstellar dust of the Pistol Nebula , this variable hypergiant will pop out as a bright blue stunner when viewed through a telescope . Other stellar sights include Eta Sagittarii , a multi-star system with a red giant irregular variable , Alpha Sagittarii , a blue dwarf with an apparent visual magnitude of 3.96 , Beta Sagittarii , which is actually a pair of star systems , and Ross 154 , a red dwarf flare that is one of the closest stars to our Sun . In addition to its bounty of stars , Sagittarius is rich in deep sky targets
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