Sky's Up July-September 2017 - Page 10

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
Sky ’ s Up
rising star Astronomy activist Science enthusiast finds ideal outlet in outreach COURTESY OF Sierra Bradley As the winner of the Astronomical League’s 2017 Horkheimer/ Smith Youth Service Award, Bradley was given the opportunity to speak at the Northeast Astronomy Forum (NEAF) in Suffern, N.Y. in April. At just 18 years old, Sierra Bradley has already received an impressive astronomy accolade for her work as a volunteer outreach educator. Earlier this year, the Astronomical League named Bradley as the winner of its 2017 Horkheimer/Smith Youth Service Award in recognition of her tireless efforts to bring people into the astronomy fold. Bradley embarked on her outreach path a few years ago through the Roanoke Valley Astronomical Society. The organization’s events provided the perfect way to share her longtime love of science with others, and she embraced the opportunities wholeheartedly. Although recognition was never her motivation, her dedication sparked RVAS President Dan Chrisman to nominate Bradley for the esteemed award. “Sierra Bradley is an excellent role model and exceptionally mature for her age. She is very comfortable during astronomy outreach interacting with those four years old to 84 years old,” Chrisman said. “The Roanoke Valley Astronomical Society and the Astronomical League are pleased to have her as a very active member and quite excited as she begins the next phase of her studies.” In addition to a cash prize, the award included an invitation to speak at the renowned Northeast Astronomy Forum in Suffern, N.Y. “The NEAF conference was an incredible experience, and I hope to go back next year,” Bradley said. “It was a great opportunity to see how science is taught through a variety of exhibits and lectures.” In this Rising Star Q&A feature, Bradley discusses her outreach efforts and reflects on the importance of science in her life. COURTESY OF Sierra Bradley 10 Sky ’ s Up When and why did you become interested in astronomy? I became interested in astronomy about four years ago when I moved to Virginia. My father knew I loved science, so he introduced me to the Roanoke Valley Astronomical Society. He took me to the organization’s outreach events to get me started. Most of the events are geared towards little kids to get them interested in science. We have several games set up that teach rudimentary astronomy. I was so enthused about teaching the kids, I began attending more and more RVAS meetings so that I could learn more about what I was teaching. COURTESY OF Sierra Bradley Bradley and a colleague work the RVAS booth at the Science Center of Western Virginia’s Science Spooktacular event. What kind of outreach activities are you involved in? For each outreach event, we (other RVAS members and I) typically have three or four activities for the young visitors to enjoy. My main job is to run a planetary sorting game. We have cards with the names and pictures of each planet on them, as well as miniature replicas of each planet. The kids must sort those cards based on the order of the planets, and then try to determine which planet replica goes with each card based on its size relative to the other replicas. I help the kids sort the planets by teaching them a little mnemonic: My Very Excellent Mother Just Served Us Nachos! What is the most rewarding part of doing astronomy outreach? The most rewarding part of doing astronomy outreach is getting to see so many kids who are interested in science. It’s wonderful seeing all the young minds want to learn and explore the world. What activities and sights generate the most excitement from your audience when you are doing outreach? Our most popular activity would have to be the scales. We have several scales FB6rpV6W'6vVBvVvFffW&VBWBvR6fRRf"FRBWfV6WBvRWBFW6R&vBWBg&BFGG&7BFRGFVFb76W'6'WfW'RGVG2@6G&VƖRw&fFFRFv&G2FW6R66W2FR6G&VfRFRWFW"66R'WBFV"&VG0&VfW"FR6WB66R6( 0W