Dark round objects

• by Ghost_Sheep_SWR

  I think I have come across these before, but don't really know what they are.

  Here is an example from SDSS, and a PanSTARRS image which seems (faintly) to contain the same object.

  

  

  They look perfectly round but also very dark. Are they very cool foreground stars or simply chance artifacts?

  Posted January 7, 2017 11:09 PM

• by planetaryscience

  I can't seem to see the same feature in the pan-STARRS image. I would attribute it simply to artifacts, especially considering I can see at least two other apparently similar formations at 6:30 and 7:30 to the galaxy.

  Posted January 8, 2017 4:00 AM