{"id":33482,"date":"2025-09-08T06:00:15","date_gmt":"2025-09-08T10:00:15","guid":{"rendered":"https:\/\/www.monsffa.ca\/?p=33482"},"modified":"2025-09-06T10:35:43","modified_gmt":"2025-09-06T14:35:43","slug":"a-sigmoid-eruption-on-the-sun","status":"publish","type":"post","link":"https:\/\/www.monsffa.ca\/?p=33482","title":{"rendered":"A SIGMOID ERUPTION ON THE SUN"},"content":{"rendered":"<p align=\"left\"><span style=\"color: #000000;\"><strong>If the sky is clear on the 7th, look for auroras.&#8211; CPL<\/strong><\/span><\/p>\n<p align=\"left\"><strong><span style=\"color: #ff0000;\">A SIGMOID ERUPTION ON THE SUN:<\/span><\/strong> When you see an &#8220;S&#8221; on the sun, it usually means something is about to explode. On Sept. 4th, NASA\u2019s Solar Dynamics Observatory recorded a textbook <a href=\"https:\/\/www.newscientist.com\/article\/dn16999-sigmoids-on-the-sun-could-help-predict-space-storms\/\">sigmoid eruption<\/a>:<\/p>\n<p align=\"center\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/spaceweather.com\/images2025\/04sep25\/sigmoid_anim_strip.gif\" alt=\"\" width=\"519\" height=\"270\" \/><\/p>\n<p align=\"left\">Researchers have long known that sigmoid structures in the sun&#8217;s atmosphere herald strong explosions. Their magnetic field lines are twisted like a slinky. When enough tension builds up, they un-twist explosively.<\/p>\n<p align=\"left\">This sigmoid hurled a dark plume of plasma more than 700,000 km long into space. The plume is dark because the plasma inside is relatively cool and dense&#8211;two qualities that can make potent CMEs.<\/p>\n<p align=\"center\"><a href=\"https:\/\/spaceweather.com\/images2025\/04sep25\/darkplasma.gif\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/spaceweather.com\/images2025\/04sep25\/darkplasma_crop_strip.gif\" alt=\"\" width=\"520\" height=\"384\" \/><\/a><\/p>\n<p align=\"left\">The explosion hurled <a href=\"https:\/\/spaceweather.com\/images2025\/04sep25\/nasamodel.gif\">a CME<\/a> directly toward Earth. NOAA and NASA models agree that it will reach our planet on Sept. 7th. The impact could spark a <a href=\"https:\/\/spaceweather.com\/glossary\/g1.jpg\">G1<\/a> to <a href=\"https:\/\/spaceweather.com\/glossary\/g2.jpg\">G2<\/a>-class geomagnetic storm with high-latitude auroras visible during the lunar eclipse. <strong> CME impact alerts:<\/strong> <a href=\"https:\/\/spaceweatheralerts.com\">SMS Text<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>If the sky is clear on the 7th, look for auroras.&#8211; CPL A SIGMOID ERUPTION ON THE SUN: When you see an &#8220;S&#8221; on the sun, it usually means something is about to explode. On Sept. 4th, NASA\u2019s Solar Dynamics Observatory recorded a textbook sigmoid eruption: Researchers have long known that sigmoid structures in the &hellip; <a href=\"https:\/\/www.monsffa.ca\/?p=33482\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">A SIGMOID ERUPTION ON THE SUN<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":645,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[133],"tags":[217,1789,276],"class_list":["post-33482","post","type-post","status-publish","format-standard","hentry","category-astronomy-news","tag-auroras","tag-sigmoid","tag-sun"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts\/33482","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/users\/645"}],"replies":[{"embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=33482"}],"version-history":[{"count":1,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts\/33482\/revisions"}],"predecessor-version":[{"id":33483,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts\/33482\/revisions\/33483"}],"wp:attachment":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=33482"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=33482"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=33482"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}