Galaxy Zoo Talk

bright green and red image

  • suelaine by suelaine

    Why does Skyserver show this image as two objects, one bright red and the other bright green?


  • JeanTate by JeanTate in response to suelaine's comment.

    Cool! 😄

    This is very rare (in my experience), especially in DR8 (and it's the same in DR10). It's an #artifact (obviously), caused by at least one of the images* being misaligned. Here's the field, zoomed out (per DR10):

    enter image description here

    If SDSS images were like postage stamps, this would be a rare variety (or whatever philatelists call printing mistakes), and it'd be worth big $ ...

    No doubt someone will soon tell the SDSS folk and it'll be fixed. That person could be you, if you're interested; look for the email addy of the SDSS Helpdesk ...

    *the images we see are produced by combining three separate images (actually just data), one taken through the SDSS' g-band filter (mapped to B in an RGB JPEG), one through the r-band one (G), and the i (R). In this case I'd say it's the i-band filter that's misaligned.