Jump to content

Wikipedia:Reference desk/Archives/Science/2017 July 28

From Wikipedia, the free encyclopedia
Science desk
< July 27 << Jun | July | Aug >> July 29 >
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


July 28

[edit]

Where to find timelapse images of Sun (ultraviolet, I suppose but I don't know)

[edit]

This video is a timelapse of the Sun from the NASA SDO (solar something observatory) but it's missing the lower half and some of the solar flares etc are cropped off. Where in NASA's archive can I find the original images to see if a better video can be constructed from them? I was hoping to make a nice animated desktop wallpaper --145.255.246.166 (talk) 19:46, 28 July 2017 (UTC)[reply]

The "something" is the Solar Dynamics Observatory. That article includes this nice 7-year timelapse video of the full sun in the 'Gallery' section: [1] — The SDO image gallery is here, and this Helioviewer might be useful if you are ambitious enough to attempt creating your own video. — 2606:A000:4C0C:E200:E465:CA4F:4607:5398 (talk) 22:04, 28 July 2017 (UTC)[reply]
Thanks very much; that link to HeliosViewer is very much appreciated since it looks about perfect for what I want. Here is an image made from two different sources and you can see there's a black border around the Sun. Is that because the information is unattainable due to the glare from the Sun or is there a way to get this filled in? I'd like to make a video without any missing information like that. I found this link to a heliosviewer forum but it doesn't seem to be working at the moment. Do you know whether it is still active? --145.255.241.195 (talk) 12:06, 29 July 2017 (UTC)[reply]
Some parts outside the shield are so bright the expensive modern detector is overwhelmed. They go full white. Imagine the parts near the surface! This doesn't mean that the stuff outside the disc is bright in everyday terms - little or none of that would be visible to the naked eye in a solar eclipse. The Sun's atmosphere is millions of degrees - hundreds of times hotter than the surface but it's at least 300,000,000,000,000 times thinner than air so it ends up very dim (a thin layer (only a few thousand km) of the Sun's atmosphere is different but it's almost literally apple vs skin thin). The Sun's outer atmosphere never really ends till several times the distance of Pluto, it just gets dimmer and dimmer and SOHO has a camera that shows 16 Sun widths from the center and can see parts 100,000,000 times dimmer than the inner corona (and 100,000,000,000,000 times dimmer than the surface). The C1 camera could see 0.1 Sun widths from the Sun before it broke and 3 corona cameras of different sensitivity were needed to cover that brightness range. (you can see movies of those online but only in 1K, at a decent frame rate the flares move so fast in C2 that they look like explosions (only 5 frames per hour)) Sagittarian Milky Way (talk) 17:05, 29 July 2017 (UTC)[reply]
Best source i know for such stuff is here, the image- and movie- archive of the webpage of the Solar Influences Data Analysis Center (SIDC) of the Royal Observatory of Belgium. --Kharon (talk) 18:36, 29 July 2017 (UTC)[reply]