Real colors of Andromeda?

[T-WING]

Hi,

We see andromeda almost every day in different colors, level of details and so on and almost every time I photograph it, it comes out differently.

This came out this time more reddish-yellowish, don't know why.. Perhaps stacking and rgb-alignment has something to do with it?

Or maybe the last two weeks of clear skies have taken their toll

Lights x67 @ISO1250

Darks x12

Bias x20

SW200PDS + DSLR (Samsung NX1)

The need for a focal reducer or different scope is clearly visible..

Clear skies!

TW

[laudropb]

Very nice image. Are the differences in colour real or due to different processing ?

[T-WING]

Very nice image. Are the differences in colour real or due to different processing ?

The differences are real. Usually it's reddish like this but sometimes more to the blue-grey.

It's highly noticeable when processing rgb curves. In this case turning up the R only affects the galaxy cloud and not the surrounding stars.

I'm keeping the camera settings for tonight just to make sure.

We've also had a lot of auroras and other polar light might be also be interfering and messing with colors. Wild speculation..

Andromeda seems like an easy target but sure is a wolf in a sheep's clothing

[jtlandreneau]

I've noticed the same thing, even with my own images between different nights. I've given up trying to figure out what the actual colors are, focus instead on making it not look like it has fake colors

[ollypenrice]

The colour is very difficult on this, the hardest colour challenge I've ever come across in any object. We know from the astrophysics that the central bulge stars are redder and the spiral arms contain the younger and hotter blue stars as well as the reds of the HII regions.

Like M42, M31 is popular because it is bright but therein lies its difficulty as well. M31 has a very, very extended outer glow which is incredibly faint and it also contains a very bright core which easily saturates. Trying to show both is about as hard as it gets.

Olly