  {"id":5308,"date":"2012-03-23T14:13:26","date_gmt":"2012-03-24T00:13:26","guid":{"rendered":"http:\/\/www.hawaii.edu\/news\/?p=5308"},"modified":"2021-04-21T11:16:57","modified_gmt":"2021-04-21T21:16:57","slug":"suns-diameter","status":"publish","type":"post","link":"https:\/\/www.hawaii.edu\/news\/2012\/03\/23\/suns-diameter\/","title":{"rendered":"Sun\u2019s diameter measured with unprecedented accuracy"},"content":{"rendered":"<span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading time: <\/span> <span class=\"rt-time\"> &lt; 1<\/span> <span class=\"rt-label rt-postfix\">minute<\/span><\/span><figure id=\"attachment_5366\" aria-describedby=\"caption-attachment-5366\" style=\"width: 630px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2012\/03\/mercury-transit.jpg\" alt=\"mercury\" width=\"620\" height=\"310\" class=\"size-full wp-image-5366\" srcset=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2012\/03\/mercury-transit.jpg 620w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2012\/03\/mercury-transit-260x130.jpg 260w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><figcaption id=\"caption-attachment-5366\" class=\"wp-caption-text\">Mercury&#8217;s path across the solar disk as seen from SOHO on November 8, 2006 (image from NASA)<\/figcaption><\/figure>\n<p class=\"clear-photo\">A group of scientists from <span aria-label=\"Hawaii\">Hawai&#699;i<\/span>, Brazil and California has measured the diameter of the Sun with unprecedented accuracy by using a spacecraft to time the transits of the planet Mercury across the face of the Sun in 2003 and 2006. Their scientific paper has been accepted by the <em>Astrophysical Journal<\/em>.<\/p>\n<p>The measurements of the Sun&#8217;s size were made by University of <span aria-label=\"Hawaii\">Hawai&#699;i<\/span> at M&#257;noa Institute for Astronomy scientists <strong>Marcelo Emilio<\/strong> (visiting from Ponta Grossa, Brazil), <strong>Jeffrey Kuhn<\/strong> and <strong>Isabelle Scholl<\/strong> in collaboration with Rock Bush of Stanford University. They used the Michelson Doppler Imager aboard <abbr>NASA<\/abbr>&#8217;s Solar and Heliospheric Observatory to make the measurements.<\/p>\n<p>They measured the Sun&#8217;s radius as 696,342 km (432,687 miles) with an uncertainty of only 65 km (40 miles). This was achieved by using the solar telescope aboard a <abbr>NASA<\/abbr> satellite, thereby bypassing the blurring caused by Earth&#8217;s atmosphere that occurs when observations are made from the ground.<\/p>\n<p>&ldquo;Transits of Mercury occur 12&#8211;13 times per century, so observations like this allow us to refine our understanding of the Sun&#8217;s inner structure, and the connections between the Sun&#8217;s output and Earth&#8217;s climate,&rdquo; said Kuhn.<\/p>\n<p>The team is preparing to observe the transit of Venus across the Sun on June 5, 2012. They expect these observations will improve the accuracy of their solar size measurement even further.<\/p>\n<p><a href=\"http:\/\/www.ifa.hawaii.edu\/info\/press-releases\/solar_radius\/\">Read the news release for more.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Institute for Astronomy scientists Marcelo Emilio, Jeffrey Kuhn and Isabelle Scholl measure the diameter of the Sun.<\/p>\n","protected":false},"author":16,"featured_media":5364,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[35,158,9],"class_list":["post-5308","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","tag-institute-for-astronomy","tag-publication","tag-uh-manoa","entry","has-media"],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2012\/03\/mercury-transit-f.jpg","_links":{"self":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/5308","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/comments?post=5308"}],"version-history":[{"count":13,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/5308\/revisions"}],"predecessor-version":[{"id":139915,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/5308\/revisions\/139915"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/media\/5364"}],"wp:attachment":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/media?parent=5308"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/categories?post=5308"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/tags?post=5308"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}