blue nucleus

• by Machiel

  what's the blue nucleus?

  Posted February 22, 2013 11:42 AM

• by vrooje admin, scientist

  This looks to me like it might be an AGN in Hubble. The blue part of the color images is taken with a different instrument than the green and red, so sometimes when you have an unresolved source the blue profile is slightly different than the red/green, so the nucleus looks blue. AGN are unresolved, and so are foreground stars. How to tell the difference just by looking? I think I can see a bit of extended galaxy signal underneath this source too, which would make it more likely to be an AGN than a foreground star.

  Posted February 22, 2013 12:03 PM

• by Machiel

  Thanks!

  Posted February 23, 2013 9:56 AM