Circle

• by lordhuck

  What is that circle?

  Posted June 25, 2014 9:29 AM

• by scibuff

  Could be many things - but most likely it is a glow which commonly accompanies diffraction spikes - see an example here >>> http://mirasolinstitute.org/obs_mishaps/images/supersaturated1.gif

  Posted June 25, 2014 8:28 PM

• by planetaryscience

  in this case, it looks like the similar lens-reflection artifact. see here

  Posted July 9, 2014 12:01 AM

• by Dr.Asteroid scientist, admin

  The circle is called a ghost. Basically it's a VERY out of focus image of a star. The star image hits the detector, but some of the light will reflect - not much but a little. That light bounces back up to the window on the detector (which is not very reflective, but a little) and bounces back down to the detector. Every single star has one, but you need a really bright one to fill it out and see it against background.

  Posted July 9, 2014 12:16 AM

• by planetaryscience

  Is that particular name for the artifact based on the hashtag I used to classify it by, or did I serendipitously use the exact given term for what the artifact had previously been known by? I'm betting on the former. 😛

  Posted July 9, 2014 2:56 AM

• by ElisabethB

  Actually it is the latter. 😄

  Posted July 9, 2014 9:31 AM

• by planetaryscience

  oh wow. xD

  Posted July 9, 2014 9:49 PM