Some deep space objects are visible with the naked eye, even though they aren't stars. These are not included in the Real Stars SkyDome

I am selling a companion prodcut, "Real Stars HDRI Collection" on Blender Market with a few HDRIs generated using this SkyDome. 

Older versions of these HDRIs have been available on the Unity Asset Store for the last 2 years. This is a new and improved version made entirely in Blender.

The original skyboxes on Unity are available for free, and you're welcome to check them out: https://assetstore.unity.com/packages/3d/environments/sci-fi/real-stars-skybox-lite-116333

An extended version with higher resolution images and programmatic control over the position of the stars is available in a "Plus" version: https://assetstore.unity.com/packages/3d/environments/sci-fi/real-stars-skybox-plus-151290

This was done using Blender's motion blur feature. I set the shutter to be open for 1 frame and increased the "Minutes Per Frame" property on the StarController object to 60 - so the amout of movement of the stars is what you would expect from a 1 hour exposure in real life.

I also tweaked the star materials to get a look I liked. I added an HSV node to turn down the saturation of the colour going into the emission node for each star. I also turned down the maximum brightness to 10 to even the stars out a bit.

Finally, I set the Latitude property on the StarController object to 45, so Polaris was about 45 degrees above the horizon, and angled the camera to centre Polaris on one of the golden ratio points.

The ground is just a plane displaced with a noise texture and covered with a free photo of a grassy field I grabbed from the Internet.

Using real world data of over 5000 stars, I wrote a python script to create a spherical dome of individually textured mesh quads stars. Each star is positioned and coloured based on real-world astronomical data.