the colour

• by VITREO

  what I want to understand is if the colors of the galaxies are original or are added with trick photography?

  Posted January 30, 2017 10:22 AM

• by Budgieye moderator

  A complicated question.

  Firstly, some of the images are reddened to make them look further away.

  Dim New Red Objects Dec 10 2016 https://talk.galaxyzoo.org/#/boards/BGZ0000007/discussions/DGZ00027bx

  Second, the colours in SDSS are not what is perceived by the eye. These galaxies are far away, and their colour is redshifted by the expansion of the universe. So the colours are changed to make them look natural to our eyes. ie. blue stars are still blue, and not green or red.

  see

  PAGE 2 Galaxy Redshift Chart https://talk.galaxyzoo.org/#/boards/BGZ0000007/discussions/DGZ0000ulp?page=2

  PAGE 3 Spectra guide for SDSS images in Galaxy Zoo Talk https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3&comment_id=53fef2ee3d5a77490c0001b6

  Third, sometimes there are colour artifacts which are stacking errors, humidity on the night, interference by nearby stars, or random colours due to the dimness of the objects.

  Posted January 30, 2017 11:01 AM