326,160ly is the current size limit for procedural galaxies in space engine. 

Planets are not generated around stars less than 1e6 years old.

That second image is pretty trippy.  What's going on in the last one?

That is the accretion disk of a black hole peaking through the clouds of a Titan planet.

https://steamuserimages-a.akamaihd.net/ugc/821189139043200112/43C692B2081443B028AC2B4DF09DF6276FD38B03/ https://steamuserimages-a.akamaihd.net/ugc/821189139043200239/EE880183CDCDA59FD97DCC52C343119B35B73B97/ https://steamuserimages-a.akamaihd.net/ugc/821189139043199635 ...

https://steamuserimages-a.akamaihd.net/ugc/821189139032421529/D28DBA99459C2224B8D91D363E20281D0DE5F529/ https://steamuserimages-a.akamaihd.net/ugc/821189139032421409/5237DCCE5E29370946C44384294C2E52BF741451/ https://steamuserimages-a.akamaihd.net/ugc/809929916640956967 ...

https://steamuserimages-a.akamaihd.net/ugc/809929916640673119/B1577CF85E6C8354E7BBAB5A2151642C706935C9/ https://steamuserimages-a.akamaihd.net/ugc/809929916635998087/6616CE9D72986B5618CDA8C02C691560140AD874/ https://steamuserimages-a.akamaihd.net/ugc/809928961035254044 ...

Yup.  Exposure is very fun to play with in the latest beta.

Do you have Version 0.981 or 0.980?

Here is the location for the first one.  RS 0-3-338-124-18175-8-2603975-688

http://images.akamai.steamusercontent.com/ugc/91599662177649393/36554FA104D376B3D081EB4E9B4ACAA918AA1A17/ http://images.akamai.steamusercontent.com/ugc/91599474209586982/FFEA01B7168933BC51DFB2F5FF1A7A7FFF723E06/ http://images.akamai.steamusercontent.com/ugc/91599028252845394 ...

I actually went on and found other asteroids with atmospheres to see how common the bug is. Very uncommon and hard to catch indeed, as they mostly appear in asteroid rings around gas giants, which makes them unlisted in the solar system browser. This is the smallest one I've found so far.
http ...

This asteroid has a tenuous H2 atmosphere and is over 3500K.