Question

Does anyone have a suggested methodology for visualising the data in a star catalogue such as the Bright Star Catalogue.

I’m thinking that there would be a notional sphere and a viewpoint i.e. at the center of that sphere with two vectors representing the view direction and view horizons.

I would then somehow project from the star catalog Celestial coordinates
coordinates (as point on the sphere) onto the viewport and draw a coloured pixel based on the color temperature of that star.

Can anyone provide any hints or suggestions?

Could it be done using billboards in OpenGL ?

or maybe a list of GL_POINTS

Answer 1

You are trying to project points on a sphere onto a plane — which is what map projections do. So yes, there are lots of resources for doing just that. If you can’t find any, comment and I’ll dig some out for you.

For the celestial sphere you are looking out towards the ‘surface’ of the sphere from inside, rather than, when you look at a map, from a notional point above the surface of the Earth looking down. But the maths is the same. And for the celestial sphere if you are just making nice pictures, you can stick to spherical maths, not all the ugly stuff that has to cope with an oblate spheroid with bumps like the Earth.