{"id":633,"date":"2014-08-24T23:35:52","date_gmt":"2014-08-24T21:35:52","guid":{"rendered":"http:\/\/freebook.fernglas-astronomie.de\/?page_id=633"},"modified":"2014-08-24T23:35:52","modified_gmt":"2014-08-24T21:35:52","slug":"aquarius","status":"publish","type":"page","link":"http:\/\/freebook.fernglas-astronomie.de\/?page_id=633","title":{"rendered":"Aquarius"},"content":{"rendered":"

As part of the zodiac, the \u201cWater-pourer\u201d Aquarius is known since ancient times. It is, however, a very faint constellation, since none of its stars are brighter than 2.8m<\/sup>. Nevertheless, it contains a number of interesting objects for amateur astronomers, including two planetary nebulae. The extended Helix Nebula appears in the binocular as a patch of light, while the Saturn Nebula (NGC 7009) is only an object for telescopes. However, it was the first planetary nebula which was recognized as such \u2013 in 1782 by Herschel.<\/p>\n

M 2<\/em><\/strong> can be seen in binoculars only as a small patch of light or a faded star of 6.3m<\/sup>, yet its 100,000 stars make it one of the most luminous globular clusters in our galaxy. Its diameter is about 150 light-years, and it is not quite spherical, but appears slightly flattened. M\u20092 is only about half as large as Omega Centauri, the largest globular cluster in our galaxy. 30,000-50,000 light-years separate us from M\u20092.<\/p>\n

The Helix Nebula (NGC 7293)<\/em><\/strong> is only 450 to 700 light-years away, yet this planetary nebula is no small challenge to the observer. Its overall brightness of 7.3m<\/sup> is spread over an area of 12 \u00d7 16 arcmin, which corresponds to approximately half the full Moon \u2013 the Helix has a correspondingly low surface brightness. In a pair of 10\u2009\u00d7\u200950 binoculars you can find it under a very dark sky as a dim, gray patch of light, while it is a very challenging object in brighter regions. The 13.3m<\/sup> central star is a challenge even for telescopes \u2013 the 180,032\u00b0 F (100,000\u00b0 C) hot stellar remnant remains invisible in binoculars.<\/p>\n","protected":false},"excerpt":{"rendered":"

As part of the zodiac, the \u201cWater-pourer\u201d Aquarius is known since ancient times. It is, however, a very faint constellation, since none of its stars are brighter than 2.8m. Nevertheless, it contains a number of interesting objects for amateur astronomers, including two planetary nebulae. The extended Helix Nebula appears in the binocular as a patch … Aquarius<\/span> weiterlesen →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":618,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-633","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/633","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=633"}],"version-history":[{"count":1,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/633\/revisions"}],"predecessor-version":[{"id":634,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/633\/revisions\/634"}],"up":[{"embeddable":true,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/618"}],"wp:attachment":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=633"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}