{"id":88617,"date":"2021-09-04T18:44:14","date_gmt":"2021-09-04T17:44:14","guid":{"rendered":"http:\/\/www.astb.se\/cassiopeiabloggen\/?p=88617"},"modified":"2021-09-04T19:05:47","modified_gmt":"2021-09-04T18:05:47","slug":"nr-62-2021","status":"publish","type":"post","link":"https:\/\/www.astb.se\/cassiopeiabloggen\/2021\/09\/04\/nr-62-2021\/","title":{"rendered":"Nr 62 2021"},"content":{"rendered":"\n

M 15 \u00f6ver Malm\u00f6<\/h2>\n\n\n\n

H\u00f6stm\u00f6rkret \u00e4r p\u00e5 int\u00e5gande och h\u00e4r kommer s\u00e4songens f\u00f6rsta Deep Sky Object fr\u00e5n “Mt Hindby”, Hans Hilderfors<\/strong> boende i Malm\u00f6-med maffigt teleskop. Om optik och teknik – kolla tidigare bloggar. <\/p>\n\n\n\n\n

\"\"<\/a><\/p>\n\n\n

BL\u00c5S UPP BILDEN P\u00c5 DIN SK\u00c4RM! Foto: Hans Hilderfors<\/em><\/p>\n\n\n\n

– En bild p\u00e5 Messier 15, en klotformig stj\u00e4rnhop i Pegasus. Den inneh\u00e5ller mer \u00e4n 100\u00a0000 stj\u00e4rnor inom en sf\u00e4r med diameter p\u00e5 cirka 200 ljus\u00e5r.. Det \u00e4r en av de ljusare stj\u00e4rnhoparna p\u00e5 norra hemisf\u00e4ren med ett avst\u00e5nd till oss p\u00e5 cirka 33\u00a0000 ljus\u00e5r och en skenbar magnitud p\u00e5 6,2. Den \u00e4r k\u00e4nd sedan 1746 d\u00e5 den uppt\u00e4cktes av Giovanni Maraldi<\/strong>. Centralt i hopen tror man att det d\u00f6ljer sig ett mindre svart h\u00e5l med massan motsvarande 4000 solmassor, ber\u00e4ttar Hans.<\/p>\n\n\n\n

– Bilden tagen som vanligt fr\u00e5n Malm\u00f6 d\u00e4r tyv\u00e4rr i min omgivning ljusf\u00f6roreningarna blir v\u00e4rre f\u00f6r varje \u00e5r. Man ser allt fler utomhusbelysningar av typen LED som \u00e4r t\u00e4nda natten igenom i tr\u00e4dg\u00e5rdana.<\/p>\n\n\n\n

Ljusf\u00f6roreningarna m\u00e4ttar kamerasensorn snabbt. Ett s\u00e4tt att delvis komma runt detta \u00e4r att ta m\u00e5nga men korta exponeringar som sedan l\u00e4ggs samman och behandlas digitalt i dator. Ett annat s\u00e4tt \u00e4r att endast fotografera objekt som l\u00e4mpar sig f\u00f6r smalbandsfilter t ex nebulosor. <\/p>\n\n\n\n

– M15 har jag fotograferat genom \u201dvanliga\u201d bredbands LRGB-filter med korta men m\u00e5nga exponeringar.<\/p>\n\n\n\n

Fakta om bilden:  Optik:  Refraktor 130 mm  f\/4,5<\/p>\n\n\n\n

                             Kamera: Monokrom CCD med filterhjul<\/p>\n\n\n\n

                             Exponering:  L 300 x 30s  R,G,B  60 x 60s    Summa: 5h 30m<\/p>\n\n\n\n

                             Bildf\u00e4lt:  33′ x 25′<\/p>\n\n\n\n

                             Plats: Tr\u00e4dg\u00e5rd i Malm\u00f6 med SQM-L = 18,2 mags\/arcsec^2 <\/p>\n\n\n\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Datum: 2021-09-02\/03<\/p>\n\n\n\n

Hans bild f\u00e5r mig att fundera \u00f6ver en annan sak. N\u00e4r Gaia-sonden f\u00e5r in M 15 i sitt maskineri, hur ser det d\u00e5 ut? Jag ska be att f\u00e5 \u00e5terkomma efter koll med Gaias lundensiske skapare, v\u00e5r ASTB-medlem prof em Lennart Lindegren. <\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

M 15 \u00f6ver Malm\u00f6 H\u00f6stm\u00f6rkret \u00e4r p\u00e5 int\u00e5gande och h\u00e4r kommer s\u00e4songens f\u00f6rsta Deep Sky Object fr\u00e5n “Mt Hindby”, Hans Hilderfors boende i Malm\u00f6-med maffigt teleskop. Om optik och teknik – kolla tidigare bloggar. BL\u00c5S UPP BILDEN P\u00c5 DIN SK\u00c4RM! Foto: Hans Hilderfors – En bild p\u00e5 Messier 15, en klotformig stj\u00e4rnhop i Pegasus. Den… L\u00e4s mer »Nr 62 2021<\/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\/88617"}],"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=88617"}],"version-history":[{"count":6,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/88617\/revisions"}],"predecessor-version":[{"id":88624,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/88617\/revisions\/88624"}],"wp:attachment":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/media?parent=88617"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/categories?post=88617"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/tags?post=88617"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}