World Modeling and World Building inform each other. It can really help to have a real galactic and planetary model to play with while crafting.
With great effort, I once assembled a starmap.zip including all the constellations and their exo-planets (as of 2004). Includes stars within 50 parsecs of Sol, and is a geocentric coordinate system.
The astronomical data comes from the HYG catalog and uses the Bayer-Flamsteed (Brightstar) naming convention. 3D coordinates were calculated from luminosity values (also given), along with the stellar classification for each star.
I even made up some gamified names (related to their discovery date) for the planets, and gave them a few moons. There are over 3000 stars and over 30 exo-planets, which makes a nice looking sky.
For example, star 18 Scorpius is listed as 18 Sco in the stars.hyg.csv file:
18 Sco 16.26031482 -8.36823651 14.02524544 G1V 0.652
Also included in the zip is the line data for constellations (connect the dots). I made some icons for the constellations as well, which are nice.
Here is the line data for Scorpius from starlines.hyg.csv
9Ome1Sco 14Nu Sco
14Nu Sco Xi Sco
Xi Sco 9Ome1Sco
9Ome1Sco 7Del Sco
7Del Sco 6Pi Sco
6Pi Sco 5Rho Sco
7Del Sco 20Sig Sco
20Sig Sco 21Alp Sco
21Alp Sco 23Tau Sco
23Tau Sco 26Eps Sco
26Eps Sco 26Eps Sco
26Eps Sco 26Eps Sco
26Eps Sco 26Eps Sco
26Eps Sco Mu 1Sco
and here is the icon for Scorpius:
Should look something like this when rendered (from Earth):
Note that 18-Sco is not part of the line data, but I rendered it's location for context.
By adding attributes the planets.csv, you should be able to model any world. Again, the craft of World Building should inform the model.
For example, here are 3 acutal exo-planets orbiting 47 Ursa Major for the planets.csv file.
You can add columns to give your planets any attributes you wish.
47 UMa B Zirgu 0 1 5.2 11.21 false
47 UMa C Macbeth 0 2 10.2 11.21 true
47 UMa D York 0 3 15.2 11.21 false
Here is a video of the model in action!