They are stickied.

https://forums.sinsofasolarempire.com/449882/page/1

https://forums.sinsofasolarempire.com/449969/page/1

Also from the Steam store page.

• New stars: Skirt the boundary of a deadly black hole, avoid the deadly radiation of a spinning pulsar, and survive the crushing gravity of an impossibly dense neutron star. 
• 6 new deep space anomalies: Mine the riches in the wreckage of a devastating fleet battle or recharge at an inexplicable fountain of antimatter tearing apart the fabric of space-time. Each anomaly’s all-new gameplay effect adds variety and strategic opportunities to every map. 
• 11 dramatic random events: The fate of not just your empire but the galaxy at large will change in a heartbeat with Stellar Phenomena’s random events enabled. Stars launch volatile gases that shut down orbital operations, mobile storms wreak havoc across the solar system, and conquered factions sense your weakness and seek to reclaim their worlds.