{"id":232,"date":"2011-05-22T00:00:43","date_gmt":"2011-05-22T00:00:43","guid":{"rendered":"http:\/\/www.skycaramba.com\/blog\/?p=232"},"modified":"2011-05-23T00:33:19","modified_gmt":"2011-05-23T00:33:19","slug":"the-vulture-star","status":"publish","type":"post","link":"https:\/\/www.skycaramba.com\/blog\/2011\/05\/22\/the-vulture-star\/","title":{"rendered":"The vulture star"},"content":{"rendered":"

SkyCaramba weekly astronomy blog for the week ending May 28, 2011<\/em><\/p>\n

\"\"<\/a>The \u201csecond most important star in the sky\u201d is up all night this time of year. Vega has been described that way because it\u2019s so close and bright and easy to study.<\/p>\n

Vega\u2019s magnitude, the number representing its brightness, is almost exactly zero. It used to be exactly zero because it was the star astronomers used to calibrate their brightness measuring equipment. Today\u2019s equipment is calibrated using methods that don\u2019t require Vega to be in the sky.<\/p>\n

In 1850, Vega was the first night sky star to be photographed. It seems nobody knows what happened to the picture. It probably didn\u2019t survive. Pictures from that era were made of glass and required a lot of careful handling. Look up daguerreotype<\/em> if you want to know more.<\/p>\n

In 1872, Vega was a first photographic subject again when astronomers learned how to examine stellar spectra. The spectrum is what you see when you look at a light beam bent apart by a prism. By determining the colors in which the star shines brightest or dimmest, a scientist can tell what the star\u2019s made of.<\/p>\n

About 10,000 years ago, Vega was the northern pole star. It will be again in about 12,000 years. Stars shift around like that in our night sky because the earth is in a long slow wobble as it goes around the sun.<\/p>\n

Astronomers believe Vega is a fast rotating star, bulging at the middle, with one of its poles pointed toward us. It\u2019s rotating almost as fast as it can without flinging apart.<\/p>\n

The star is one of our closest stellar neighbors, just 25 light years away. That\u2019s close enough to easily measure its distance using the parallax method. That\u2019s a comparison of the slightly different positions things appear to be in when viewed from different places. Over six months\u2019 time, the earth moves from one side of the sun to the other and positions of the nearer stars seem to shift slightly.<\/p>\n

You\u2019ll find Vega in the constellation Lyra. It\u2019s a parallelogram with a couple stars nearby. It looks like a clapper board used in film making (the thing someone holds in front of a camera and makes a clapping noise with when the director yells Action!<\/em>).<\/p>\n

Some of the oldest stories about it say this constellation is a vulture and Vega is the Vulture Star. To the Greeks, it was a harp, sometimes still held in a vulture\u2019s claws or an eagle\u2019s wings. Apollo gave this harp to his son Orpheus who played so well he almost charmed the gods into letting his dead wife out of Hades.<\/p>\n

In Asia, Vega represents a princess who falls in love with a shepherd represented by the star Altair. They\u2019re on opposite sides of the Milky Way stream because when they\u2019re together they don\u2019t get their work done. The lovers are said to rendezvous just one night every year.<\/p>\n

I\u2019ll tell you more about Altair another time. It and Vega are part of something called the Summer Triangle.<\/p>\n","protected":false},"excerpt":{"rendered":"

Get to know the second most important star in the sky. The sun’s number one.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[138,135,133,134,136,132,137],"_links":{"self":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/232"}],"collection":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/comments?post=232"}],"version-history":[{"count":9,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/232\/revisions"}],"predecessor-version":[{"id":242,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/232\/revisions\/242"}],"wp:attachment":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/media?parent=232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/categories?post=232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/tags?post=232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}