{"id":95124,"date":"2024-02-27T19:46:59","date_gmt":"2024-02-27T18:46:59","guid":{"rendered":"https:\/\/www.astb.se\/cassiopeiabloggen\/?p=95124"},"modified":"2024-02-27T19:50:00","modified_gmt":"2024-02-27T18:50:00","slug":"nr-15-2024","status":"publish","type":"post","link":"https:\/\/www.astb.se\/cassiopeiabloggen\/2024\/02\/27\/nr-15-2024\/","title":{"rendered":"Nr 15 2024"},"content":{"rendered":"\n

“Krabbans” expansion uppm\u00e4tt p\u00e5 Mt Hindby<\/h2>\n\n\n\n

V\u00e5r ASTB:are Hans Hilderfors <\/strong>sl\u00e4pper inte greppet om Krabbnebulosan hemifr\u00e5n Hindby, Malm\u00f6. I g\u00e5r tog Hans ett spektrum fr\u00e5n Krabbnebulosan f\u00f6r att om m\u00f6jligt f\u00f6rs\u00f6ka f\u00e5 en uppskattning av dess expansionshastighet.<\/p>\n\n\n\n

Rapporten h\u00e4r:<\/p>\n\n\n\n

“Min tanke var att f\u00f6rs\u00f6ka p\u00e5visa dopplerskift vid den starkaste OIII-v\u00e5gl\u00e4ngden 5007 \u00c5. V\u00e4dret var ogynnsamt med en hel del dis som f\u00f6rv\u00e4rrade ljusf\u00f6roreningarna i Malm\u00f6.<\/p>\n\n\n\n

Med l\u00e5ng exponeringstid gick det dock att urskilja OIII-linjen. Bild 1 visar slutresultatet n\u00e4r ljusf\u00f6roreningarna subtraherats bort.<\/p>\n\n\n\n

Linjen blir elipsformad p\u00e5 grund av att gaserna i supernovarestens skal expanderar med h\u00f6g fart.<\/p>\n\n\n\n

Vi ser dopplerskift mot r\u00f6tt fr\u00e5n bakre skalet (som r\u00f6r sig fr\u00e5n oss) och skift mot bl\u00e5tt fr\u00e5n det fr\u00e4mre skalet (som r\u00f6r sig mot oss). \u00d6vre och nedre delarna har litet eller inget dopplerskift eftersom skalet h\u00e4r r\u00f6r sig vinkelr\u00e4tt ut sett fr\u00e5n v\u00e5r synaxel.<\/p>\n\n\n\n

En enkel m\u00e4tning p\u00e5 r\u00e5bilden ger att dopplerskiftet mellan linjerna  centralt \u00e4r av storleksordningen 46 \u00c5.<\/p>\n\n\n\n

Expansionshastigheten blir d\u00e5\u00a0 \u00bd x (300\u00a0000 x 46)\/5007 = 1380 km\/s vilket st\u00e4mmer bra med den g\u00e4ngse uppskattningen p\u00e5 1500 km\/s.”<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

Bild 2 visar spaltens l\u00e4ge \u00f6ver M1 under exponeringen:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n","protected":false},"excerpt":{"rendered":"

“Krabbans” expansion uppm\u00e4tt p\u00e5 Mt Hindby V\u00e5r ASTB:are Hans Hilderfors sl\u00e4pper inte greppet om Krabbnebulosan hemifr\u00e5n Hindby, Malm\u00f6. I g\u00e5r tog Hans ett spektrum fr\u00e5n Krabbnebulosan f\u00f6r att om m\u00f6jligt f\u00f6rs\u00f6ka f\u00e5 en uppskattning av dess expansionshastighet. Rapporten h\u00e4r: “Min tanke var att f\u00f6rs\u00f6ka p\u00e5visa dopplerskift vid den starkaste OIII-v\u00e5gl\u00e4ngden 5007 \u00c5. V\u00e4dret var ogynnsamt… L\u00e4s mer »Nr 15 2024<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rop_custom_images_group":[],"rop_custom_messages_group":[],"rop_publish_now":"initial","rop_publish_now_accounts":[],"rop_publish_now_history":[],"rop_publish_now_status":"pending","neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[3],"tags":[],"_links":{"self":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/95124"}],"collection":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/comments?post=95124"}],"version-history":[{"count":3,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/95124\/revisions"}],"predecessor-version":[{"id":95129,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/95124\/revisions\/95129"}],"wp:attachment":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/media?parent=95124"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/categories?post=95124"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/tags?post=95124"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}