{"id":84487,"date":"2020-06-18T19:33:59","date_gmt":"2020-06-18T18:33:59","guid":{"rendered":"http:\/\/www.astb.se\/cassiopeiabloggen\/?p=84487"},"modified":"2020-06-19T09:58:51","modified_gmt":"2020-06-19T08:58:51","slug":"nr-52-2020","status":"publish","type":"post","link":"https:\/\/www.astb.se\/cassiopeiabloggen\/2020\/06\/18\/nr-52-2020\/","title":{"rendered":"Nr 52 2020"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Tunguska-asteroiden snurrar runt solen<\/h2>\n\n\n\n<p>Ryska astronomer kommer, vad jag vet, <a href=\"https:\/\/academic.oup.com\/mnras\/article\/493\/1\/1344\/5722124\">med ett&nbsp;ganska nytt uppslag <\/a>vad g\u00e4ller den dramatiska sm\u00e4llen \u00f6ver Steniga Tunguska 30 juni 1908. L\u00e4nge har den popul\u00e4ra id\u00e9n varit f\u00f6rh\u00e4rskande att vi m\u00f6tte en kraftigt isbem\u00e4ngd himlakropp, kanske en komet, som f\u00f6r\u00e5ngades helt men \u00e4nd\u00e5 orsakade en explosion \u00f6ver Sibirien. Men nu visar de nya ber\u00e4kningarna:<\/p>\n\n\n\n<p>Tunguskah\u00e4ndelsen&nbsp;berodde p\u00e5 en&nbsp;j\u00e4rnrik&nbsp;himlakropp, kanske&nbsp;50-60 m stor, som passerade genom jordatmosf\u00e4ren, med minimal massf\u00f6rlust. Efter passagen f\u00f6rsvann asteroiden&nbsp; ut i den planet\u00e4ra v\u00e4rlden, d\u00e4r&nbsp;den nu snurrar runt solen.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"273\" height=\"215\" src=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/tunguskaMap1.jpg\" alt=\"\" class=\"wp-image-84506\" srcset=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/tunguskaMap1.jpg 273w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/tunguskaMap1-200x158.jpg 200w\" sizes=\"(max-width: 273px) 100vw, 273px\" \/><\/figure><\/div>\n\n\n\n<p>H\u00f6jden vid passagen har minimalt r\u00f6rt sig om 10-15 km och banans l\u00e4ngd genom atmosf\u00e4ren var kanske 3000 km. Angreppsvinkeln&nbsp;kan ha legat p\u00e5&nbsp;\u2264 11.5 gr, inte de 30-40 gr som tidigare antagits. Hastigheten m\u00e5ste ha r\u00f6rt sig \u00f6ver jordens flykthastighet, dvs 11&nbsp;.2&nbsp;km\u2009s\u22121 <\/p>\n\n\n\n<p>Inga som helst rester, inte ens i mikroformat, och absolut&nbsp;ingen nedslagskrater, har observerats vid omr\u00e5det. N\u00e4r luften pressades samman vid jordytan, tryckv\u00e5gen var enorm, &nbsp;slogs minst 2000 kvadratkilometer skog ut. Sp\u00e5r finns fortfarande kvar i naturen.<\/p>\n\n\n\n<p>Chockv\u00e5gen fr\u00e5n passagen noterades p\u00e5 seismografer och himlen gl\u00f6dde l\u00e4nge&nbsp;\u00f6ver norra klotet. \u00c4ven i Sverige noterades att &#8220;n\u00e5got&#8221; hade h\u00e4nt.<\/p>\n\n\n\n<p>Sista ordet sagt? S\u00e4kert inte. \u00c4ven om de rent sakastronomiska f\u00f6rklaringarna h\u00e5ller, s\u00e5 kommer fortfarande ufofolket och konspirationsteoretiker inte att ge upp. Numera har ocks\u00e5 svart h\u00e5l-t\u00e4nkare blandat sig i leken. Men en metalltung Near Earth-passerande asteroid \u00e4r v\u00e4l inte s\u00e5 dumt?<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Historiskt Zoom-m\u00f6te<\/h2>\n\n\n\n<p>Jag kunde tyv\u00e4rr inte sj\u00e4lv n\u00e4rvara p\u00e5 den svensk-brittisk-finska klubbkv\u00e4llen ig\u00e5r, men h\u00e4r finns den i Youtubesf\u00e4ren. Kort som en normal gammaldags l\u00e5ngfilm.<\/p>\n\n\n\n<figure class=\"wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<div class=\"nv-iframe-embed\"><iframe title=\"Klubbm\u00f6te via Zoom i Astronomiska S\u00e4llskapet Tycho Brahe 2020-06-17\" width=\"1200\" height=\"675\" src=\"https:\/\/www.youtube.com\/embed\/3ejjljfnOK8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe><\/div>\n<\/div><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Inga vanliga planetariska nebulosor<\/h2>\n\n\n\n<p>ESA\/NASA\/Hubble Space Telescope har tagit tv\u00e5 bilder av planetariska nebulosor, bilder om vilka vi spontant m\u00e5ste s\u00e4ga:&nbsp;We like!<\/p>\n\n\n\n<p>NGC 6302 och &nbsp;NGC 7027 tillh\u00f6r tv\u00e5 av de mest gas-, stoft- och dammrika planetariska nebulosor vi k\u00e4nner till. De tillh\u00f6r universums mera &#8211; astronomiskt sett &#8211; snabbut\/avvecklande himlakroppar, livsl\u00e4ngden \u00e4r kort. I dessa nebulosors mittar ligger, tros det, tv\u00e5 stj\u00e4rnor som snurrar runt varandra, d\u00e4rav deras&nbsp; beteckning &#8220;dynamic duo&#8221;. Detta betyder en hel del om stj\u00e4rnorna har olika storlekar och massor.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"473\" src=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/heic2011a1-1-1024x473.jpg\" alt=\"\" class=\"wp-image-84519\" srcset=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/heic2011a1-1-1024x473.jpg 1024w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/heic2011a1-1-300x139.jpg 300w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/heic2011a1-1-768x355.jpg 768w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/heic2011a1-1-200x92.jpg 200w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/heic2011a1-1.jpg 1280w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"has-text-align-center\"><em>Bildk\u00e4lla: NASA, ESA,&nbsp;och J. Kastner (RIT)<\/em><\/p>\n\n\n\n<p><br><a href=\"https:\/\/www.spacetelescope.org\/news\/heic2011\/?lang\">Hubble-messet rekommenderas.<\/a><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Till\u00e5tet att skratta<\/h2>\n\n\n\n<p>Man kan alltid diskutera om astronomer har humor. Ibland tar de kosmos p\u00e5 f\u00f6r stort allvar, i <em>V\u00e4rld och Vetande,<\/em> <strong>Knut Lundmarks <\/strong>tidskrift, skrev&nbsp;denne &nbsp;dock sj\u00e4lv ett par artiklar p\u00e5 temat humor och stj\u00e4rnor, men det \u00e4r s\u00e4llan vi till\u00e5ts dra p\u00e5 smilbanden i v\u00e5r lilla stora vetenskap. Tycker jag.<\/p>\n\n\n\n<p>S\u00e5 tack till <strong>Christian Vestergaard<\/strong>, som skickat \u00f6ver detta nyhetsatelegram fr\u00e5n IAU 1977, f\u00f6rfattat av nyhetsbyr\u00e5ns legendariske chef <strong>Brian G Marsden<\/strong>:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"710\" height=\"960\" src=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/Brian-G.-Marsden-gag.jpg\" alt=\"\" class=\"wp-image-84516\" srcset=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/Brian-G.-Marsden-gag.jpg 710w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/Brian-G.-Marsden-gag-222x300.jpg 222w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/Brian-G.-Marsden-gag-148x200.jpg 148w\" sizes=\"(max-width: 710px) 100vw, 710px\" \/><\/figure>\n\n\n\n<p>L\u00e4s och njut av galenskaperna!<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">PS. Venus-ockultationen 19 juni\u2026<\/h2>\n\n\n\n<p>.. st\u00e4lldes in, men <strong>Jon Saalbach<\/strong> var i alla fall p\u00e5 TBO och hade laddat Meaden. Om utifall att, men&#8230; n\u00e4.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"576\" height=\"1024\" src=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-576x1024.jpg\" alt=\"\" class=\"wp-image-84522\" srcset=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-576x1024.jpg 576w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-169x300.jpg 169w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-768x1365.jpg 768w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-113x200.jpg 113w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-864x1536.jpg 864w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-1152x2048.jpg 1152w, https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/IMG_20200619_095335176_HDR-scaled.jpg 1440w\" sizes=\"(max-width: 576px) 100vw, 576px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Glad midsommar<\/h2>\n\n\n\n<p>Jag fick en trevlig smiley fr\u00e5n <strong>Pettzy Ahlstr\u00f6m<\/strong>, v\u00e5r ASTB-medlem, h\u00e4rom dan. Jag tycker den&nbsp; fungerar extremt v\u00e4l i dessa coronatider. Nu g\u00e5r vi ju dessutom mot m\u00f6rkare tider, gudskelov!<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"400\" height=\"400\" src=\"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-content\/uploads\/2020\/06\/Smiling-globe.gif\" alt=\"\" class=\"wp-image-84517\"\/><\/figure>\n\n\n\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tunguska-asteroiden snurrar runt solen Ryska astronomer kommer, vad jag vet, med ett&nbsp;ganska nytt uppslag vad g\u00e4ller den dramatiska sm\u00e4llen \u00f6ver Steniga Tunguska 30 juni 1908. L\u00e4nge har den popul\u00e4ra id\u00e9n varit f\u00f6rh\u00e4rskande att vi m\u00f6tte en kraftigt isbem\u00e4ngd himlakropp, kanske en komet, som f\u00f6r\u00e5ngades helt men \u00e4nd\u00e5 orsakade en explosion \u00f6ver Sibirien. Men nu visar&hellip;&nbsp;<a href=\"https:\/\/www.astb.se\/cassiopeiabloggen\/2020\/06\/18\/nr-52-2020\/\" rel=\"bookmark\">L\u00e4s mer &raquo;<span class=\"screen-reader-text\">Nr 52 2020<\/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\/84487"}],"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=84487"}],"version-history":[{"count":22,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/84487\/revisions"}],"predecessor-version":[{"id":84523,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/84487\/revisions\/84523"}],"wp:attachment":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/media?parent=84487"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/categories?post=84487"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/tags?post=84487"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}