{"id":10803,"date":"2024-11-08T10:04:52","date_gmt":"2024-11-08T14:04:52","guid":{"rendered":"https:\/\/starlightcascade.ca\/blog\/?p=10803"},"modified":"2024-11-08T10:04:52","modified_gmt":"2024-11-08T14:04:52","slug":"saturn-20241107","status":"publish","type":"post","link":"https:\/\/starlightcascade.ca\/blog\/2024\/11\/saturn-20241107\/","title":{"rendered":"Saturn 20241107"},"content":{"rendered":"

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

Out last evening (Thursday Nov 7) imaging Saturn.<\/p>\n

This is the best image of the best 10% of 10K frames exposed at 18ms. Saturn was only 35 degrees in altitude, seeing was poor, transparency was poor and the was a crescent moon nearby in the sky.<\/p>\n

Saturns diameter is approx 18 arcsec. This was processed with autostakkert, regixstax, gimp and imagemagick.<\/p>\n

I can’t make out any belts or bands in the southern hemisphere and see only 3 regions in the north. Saturns shadow shows on the rings on the left side of the planet and the rings are dim.<\/p>\n

So.. I was having to manually adjust the tracking about every two runs of 180 seconds, as Saturn (in an 800×800 cutout box, in a 1200×1200 region of interest) moved from one side of the FOV to the other. How bad is the tracking I wondered? <\/p>\n

I know I have planned another polar align followed by a 2 star align in my TODO list.. but still what is a number for drift?<\/p>\n

I went to http:\/\/astronomy.tools\/calculators\/field_of_view\/ and entered my specs:
\nC9.25, x1.5 barlow asi585mc camera.
\nSystem FOV 0.18 deg x 0.1deg = 0.18 deg\/3600arcsec\/deg by 0.1deg\/3600arcsec\/deg = 648×360 arcsec<\/p>\n

Camera: 3840×2160 pixels<\/p>\n

So.. the drift of the cutout box (800×800) in 1200×1200 ROI moves 400 pixels in about 360 seconds or ~1 pixel\/sec
\n3840 pixels\/648arcsec=6 pixels\/arcsec<\/p>\n

at ~1 pixel\/sec it will take 6 seconds to moves 6 pixels or
\nit drifts at a rate of 1\/6 arcsec\/second<\/p>\n

Is that good? bad? Can others run the process for comparison?<\/p>\n","protected":false},"excerpt":{"rendered":"

Out last evening (Thursday Nov 7) imaging Saturn. This is the best image of the best 10% of 10K frames exposed at 18ms. Saturn was only 35 degrees in altitude, seeing was poor, transparency was poor and the was a crescent moon nearby in the sky. Saturns diameter is approx 18 arcsec. This was processed […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-10803","post","type-post","status-publish","format-standard","hentry","category-astronomy"],"_links":{"self":[{"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/posts\/10803","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/comments?post=10803"}],"version-history":[{"count":1,"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/posts\/10803\/revisions"}],"predecessor-version":[{"id":10805,"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/posts\/10803\/revisions\/10805"}],"wp:attachment":[{"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/media?parent=10803"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/categories?post=10803"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starlightcascade.ca\/blog\/wp-json\/wp\/v2\/tags?post=10803"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}