{"id":735,"date":"2014-08-25T21:29:29","date_gmt":"2014-08-25T19:29:29","guid":{"rendered":"http:\/\/freebook.fernglas-astronomie.de\/?page_id=735"},"modified":"2014-08-25T21:29:29","modified_gmt":"2014-08-25T19:29:29","slug":"gemini","status":"publish","type":"page","link":"http:\/\/freebook.fernglas-astronomie.de\/?page_id=735","title":{"rendered":"Gemini"},"content":{"rendered":"<p>The twins Castor and Pollux of Greek mythology were the inspiration for this constellation, and its two brightest stars are named after this pair of twins. Castor (\u03b1 Geminorum) is a six fold star only 51 light years away and with a total of 1.6<sup>m<\/sup> slightly darker than the 1.2<sup>m<\/sup> bright and 33.7 light-years away Pollux (\u03b2 Geminorum). In the lower half of the constellation, the two reddish stars \u03b7 and \u03bc show a nice color contrast to the bluish-white \u03b3 Geminorum.<\/p>\n<p>Two planets in our solar system were discovered in the Twins \u2013 Uranus was observed in the vicinity of \u03b7 for the first time in 1781, and Pluto in 1930 in the vicinity of \u03b4.<\/p>\n<p>In the center of the constellation, <strong><em>\u03b6 Geminorum<\/em><\/strong> can be found \u2013 one of the brightest variables of the Cepheid type. Its brightness varies within 10.15 days between 3.6 and 4.2<sup>m<\/sup>. Its period is not quite constant, but increases each year by 3.6 seconds. 1,200 light years separate us from it.<\/p>\n<p>It is still unknown why the brightness of <strong><em>BU Geminorum<\/em><\/strong> varies irregularly between 5.7 and 7.5<sup>m<\/sup>. Its brightness changes only slowly \u2013 perhaps it is therefore classified sometimes as an eclipsing binary, although its light curve is irregular. The distance of the star is unknown.<\/p>\n<p><strong><em>M 35<\/em><\/strong> is easy to find 2.5\u00b0 northwest of \u03b7 Geminorum. Only about half a dozen stars can be resolved with binoculars, the remaining stars blur into a shimmer. The open cluster has a diameter of about 40 light years \u2013 at a distance of 2,600 light years it appears as large as the full Moon.<\/p>\n<p><em><strong>NGC 2392<\/strong><\/em> is one of the most distant open clusters \u2013 14,000 light-years separate us from it. With a brightness of only 8.6<sup>m<\/sup> and a diameter of five minutes of arc it is a target for larger binoculars. The rather old star cluster is located near the rim of our galaxy and can only be observed because its light is hardly attenuated by interstellar dust clouds. It was formed 800 million years ago.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The twins Castor and Pollux of Greek mythology were the inspiration for this constellation, and its two brightest stars are named after this pair of twins. Castor (\u03b1 Geminorum) is a six fold star only 51 light years away and with a total of 1.6m slightly darker than the 1.2m bright and 33.7 light-years away &hellip; <a href=\"http:\/\/freebook.fernglas-astronomie.de\/?page_id=735\" class=\"more-link\"><span class=\"screen-reader-text\">Gemini<\/span> weiterlesen <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":714,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-735","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/735","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=735"}],"version-history":[{"count":1,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/735\/revisions"}],"predecessor-version":[{"id":736,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/735\/revisions\/736"}],"up":[{"embeddable":true,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/714"}],"wp:attachment":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=735"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}