1
$\begingroup$

I have been trying hard to find the star "Polaris" in the following image from ESO and Serge Brunier:

The Milky Way panorama from

From peering at other maps and simulation apps, I think it should be in the top-left quarter, relatively close to the middle (vertically), however taking the brightest starts one by one, I cannot piece together the other stars belonging to Ursa Minor (small dipper).

I want to use this image as a background in a 3D model of Earth. The projection is perfect for that purpose, I only need to rotate it in such a way that Polaris lines up with the north pole. Once that is accomplished I can rotate it around the Earth's polar axis to set the right time of day at a certain part of the year (it does not have to be 100% accurate for my purpose, but it should at least look a bit realistic to an astronomer).

One thing that makes this task quite hard with this high resolution image is that stars seem to pop in and out of existence while zooming in and out, probably due to lossy fast re-sampling algorithms used in my image viewers.

If someone with a trained eye could point out the Ursa Minor constellation for me it would save me a ton of time!

$\endgroup$
2
$\begingroup$

Here is a star map (from http://www.datasync.com/~rsf1/fun/sm-newd.gif ) given in Galactic coordinates. It appears to be presented in a similar (but not the same, since it is rectangular) projection to the one you show above.

The Galactic centre is in the middle and the Large and Small Magellanic clouds are to the lower right and oriented in the same way.

As you can see from this map, your assumption is completely correct. Ursa Major and Polaris should be situated towards the upper left hand side of the picture. Conveniently it should be on the opposite side and roughly equi-distant from the Galactic plane as M31 (which is clearly visible in the image) and at a similar (slightly lower) Galactic longitude.

I have added a copy of your image at the bottom and marked where I think Polaris is. I suggest you get hold of the higher resolution image available from Serge Brunier if you want to pick out individual stars. The way you transfrom this into equatorial coordinates for different times of the year is not as simple as you suggest.

Star map in Galactic coordinates

Modified starmap with Polaris marked

$\endgroup$
1
  • $\begingroup$ Super! thanks! Apparently I have been looking too far to the right so far. I know it is not that simple to translate into times of the year and time-of-day, but I'm making short animations where I can tweak the angles to roughly match up to what other simulation applications are showing. The first step was finding an anchor point. I have literally spent days on this before coming here for help. It would be cool if I could implement all the math, including procession and other wobbles, but if that ever becomes a requirement I'll probably be back with new questions :-). $\endgroup$ – Louis Somers Apr 26 '15 at 20:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.