Celestia Forums

Is there a feature in Celestia that let's select you a group of stars and put a lcommon label on them? And especially would allow it to assign a color to them? So that they could be seen in the galaxy map?
I was thinking about creating stellar empires and thus somehow marking their sphere of influence.

Unfortunately, Celestia does not have exactly the features you want, but there are several workarounds.

You can place labels anywhere in space using a Deep Space Catalog and either its OpenCluster or Nebula objects. They're drawn when you select the menu Render/ View Options / Galaxies Label.

One way to draw lines between stars is by adding them to celestia/data/asterisms.dat. It's a plain-text file. The lines are always blue, however. They're drawn when you select Render/ View Options/ Constellations.

Another option for making the stars distinctive is to create a DSC Nebula. Its 3D model could contain appropriate "markers": objects at the positions of the stars that are in a group, or connecting elements, or a bubble around them all. "Nebula" models can be any size. They're drawn when you select Render/ View Options/ Galaxies.

You also could create an STC (STar Catalog) which defines (unphysical) stars at the locations of the ones of interest that are extremely bright.

Do these suggestions help at all?

I like the last suggestion, Selden; that would help me a lot with my maps-

this one for instance (I tried the Cluster method but it didn't seem to work);
could you point me in the direction of a description of how to make unphysical 'bright' stars?

logs in

This is one of the maps I am trying to emulate in Celestia

http://www.orionsarm.com/galactography/ ... s_img.html

many of the locations are imaginary, but exist at a definite point in space- it would be nice to be able to see them from a respectable 'distance'...

You'd have to create an STC file (or several) which contains the HIP number, name, location, spectral class and AbsMag value for each of the stars in the group. By a "non physical" brightness, I just mean that you can set AbsMag to any value you want. A value of -13 would make all of them visible at intergalactic distances.

An example of this is the Addon I created which lists all of the O, B and M stars from the Hipparcos catalog. See http://www.lns.cornell.edu/~seb/celestia/catalogs.html#3.5.11

Since my Addon duplicates stars that already are in Celestia, those stars wind up being listed twice when you select them. Celestia doesn't care.

Recent Celestia pre-releases don't require a stars.dat, so eliminating stars.dat will eliminate the duplication: it'll only draw the stars you define in STC files.

Thanks selden,

yes these suggestions help me. now i just have to try them out and find the best method for want i am planning to do.

BTW: Your pages on Celestia are a great help into finding out what this program can really achieve and how certain things work.

Matlaf,

Thanks for the kind words.

There is, of course, yet another way to mark stars that Celestia knows about. Use the Mark function in a Cel script.

You can specify one of several different shapes, size, color and brightness. The size of a Mark is a fixed number of pixels, so it stays the same size on the screen no matter how far away you are. They're drawn when you select Render/ View Options/ Markers.