{"id":607,"date":"2014-08-24T23:05:17","date_gmt":"2014-08-24T21:05:17","guid":{"rendered":"http:\/\/freebook.fernglas-astronomie.de\/?page_id=607"},"modified":"2014-08-24T23:05:17","modified_gmt":"2014-08-24T21:05:17","slug":"leo","status":"publish","type":"page","link":"http:\/\/freebook.fernglas-astronomie.de\/?page_id=607","title":{"rendered":"Leo"},"content":{"rendered":"

This distinctive constellation has been identified with a lion for over 5,000 years. To modern amateur astronomers it is known primarily for its galaxies. The lion is also the home of the third nearest neighbor star of the Sun, the about Jupiter-sized dwarf star Wolf 359. It is only 7.6 light-years away and with 13.5m<\/sup> not an easy target even for telescopes \u2013 it remains unobservable in binoculars. Wolf 359 is located a little more than 2\u00b0 west of the 4.6m<\/sup> star \u03c7 Leonis.<\/p>\n

\u03b1 Leonis (Regulus)<\/strong><\/em> is the 1.4m<\/sup> bright main star of Leo and only 77.5 light-years away. In binoculars you can see its 8.1m<\/sup> bright companion in three minutes of arc distance. It has approximately the same distance as Regulus, but it is likely to be only an optical double star.
\nWhen Hipparchus compared the positions of Regulus and Spica in 130 A.D. to Babylonian descriptions from 200 years before, he discovered the precession of Earth\u2018s axis due to the changed position of the star. The name Regulus (Little King) goes back to Nicolaus Copernicus. Before him, the star was known as Cor Leonis (Heart of the Lions) or referred to as \u201eroyal star\u201c. In Babylonian times it was called \u201eAmil-galur\u201c, the \u201eRuler before the Flood\u201c.<\/p>\n

R Leonis<\/em><\/strong> is a Mira-type variable at a distance of 330 light-years, which was first observed in 1782 by J.A. Koch in Gdansk. Within an average of 312.4 days its brightness varies between 5.4 and 10.5m<\/sup>. The star shows a distinct red color during the maxima.<\/p>\n

M 65, M 66 and NGC 3628<\/em><\/strong> form a beautiful group of galaxies between \u03b8 and \u03b9 Leonis. The center of the 9.7m<\/sup> bright M\u200966 is the easiest target. Under optimal conditions, you can imagine the faint glimmer of the spiral arms already in 10\u00d750s with averted vision. Photographs show clearly that the 32 million light-years distant galaxy contains a lot of dust. M\u200965 is similar to M\u200966, but at 10.1m<\/sup> it\u2018s fainter. M\u200965 is 21 arc minutes to the west of M\u200966 and 56 million light-years away. Both galaxies are about nine arc minutes in width and four arc minutes in depth.<\/p>\n

0.5\u00b0 north of the two galaxies, you may find the weak shimmer of the at least 4 \u00d7 14 arc minutes wide edge-on galaxy NGC 3628. Because of its size, the 10.4m bright galaxy is visible only under very good conditions in a pair of 10\u2009\u00d7\u200950 binoculars, otherwise you need giant binoculars or better yet a telescope.<\/p>\n

\"M\u2009\u200965<\/a>
M 65, M 66 and NGC 3628 are a small group of galaxies. M 66 is in the lower part of the image in the center, M 65 to its right. The spiral arms can be seen easily as dim shimmer. The edge-on galaxy NGC 3628 can be seen as a small line in the upper half of the image.<\/figcaption><\/figure>\n

The second famous group of galaxies in Leo consists of M 95, M 96 and M 105<\/em><\/strong>. The brightest member of the group is 47 million light-years distant M\u200996 at 9.2m<\/sup>. It can be found close to the connecting line between \u03b8 and \u03c1 Leonis. M\u200995 is 42 arc minutes away from it and a 10.6m bright barred spiral galaxy.<\/p>\n

Both galaxies have a diameter of about seven minutes of arc. The bar of M\u200995 can be seen only in a telescope, then also a ring around the galaxy becomes visible, so that it reminds of the Greek letter \u0398. 1\u00b0 north of M\u200996 is the 36 million light-years distant elliptical galaxy M\u2009105. It has a diameter of 35,000 light-years and appears as a bright 9.3m<\/sup>. There is a ring of gas inside of M\u2009105 which rotates independently of the rotation of the galaxy. You need at least 10x or 15x magnification to see more of these galaxies than the core as a fuzzy star \u2013 averted vision facilitates the observation.<\/p>\n","protected":false},"excerpt":{"rendered":"

This distinctive constellation has been identified with a lion for over 5,000 years. To modern amateur astronomers it is known primarily for its galaxies. The lion is also the home of the third nearest neighbor star of the Sun, the about Jupiter-sized dwarf star Wolf 359. It is only 7.6 light-years away and with 13.5m … Leo<\/span> weiterlesen →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":591,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-607","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/607","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=607"}],"version-history":[{"count":1,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/607\/revisions"}],"predecessor-version":[{"id":609,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/607\/revisions\/609"}],"up":[{"embeddable":true,"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=\/wp\/v2\/pages\/591"}],"wp:attachment":[{"href":"http:\/\/freebook.fernglas-astronomie.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=607"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}