6 ms·
I really hate that you can see artifacts from the hex mirrors.
by spullara 4y ago
I really hate that you can see artifacts from the hex mirrors.
- ceejayoz 4y agoExplanation: https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/
- penneyd 4y agoHubble had diffractions spikes too, four of them from the struts holding the secondary mirror.
- _moof 4y agoThey aren't from the mirrors; they're from the struts.
- _xerces_ 4y agoThey're from the mirrors, just one is from the struts.
- dredmorbius 4y agoFalse. Three struts, but because of light diffraction, six spikes. There are much smaller diffraction effects which are in part due to the mirrors, but these are far smaller and not immediately evident. Both apply largely to foreground point sources, which is to say, relatively nearby stars. Distant objects with an appreciable size don't produce diffraction spikes. Read: https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/ (Via: https://news.ycombinator.com/item?id=32063220 https://news.ycombinator.com/item?id=32063220)
- Osmium 4y agoThis infographic does a nice job showing which are from the struts and which from the mirrors: https://webbtelescope.org/contents/media/images/01G529MX46J7AFK61GAMSHKSSN https://webbtelescope.org/contents/media/images/01G529MX46J7... Of course, the JWST without its struts and its mirrors wouldn't be much of a telescope! So the diffraction spikes are a part of doing business and also have the helpful side effect of allowing us to quickly know which objects are stars vs galaxies, since only the former have the really prominent spikes.
- kristianp 4y agoThey are distracting. Will they be able to dim the "lens-flares" computationally?
- colechristensen 4y agoLens flare is the wrong term but yes they do correct for them.
- deleted 4y ago[deleted]