Red Stars are very different. They do not belong to any player. Only a small amount of players have time limited access to a given Red Star (we're thinking 3-8 players depending on the star's level, likely to be tweaked). The star's lifetime is very small - probably much smaller than a day (exact amount to be determined from playtesting). After the time limit expires, Red Stars go Supernova, destroying any objects near them, including any ships the players may have left there.
The limited lifetime of Red Stars allow us to experiment with completely different gameplay and social mechanics compared to the stable, more "boring" yellow stars. It is our hope that mixing the two types of stars on someone's daily routine of playing the game will make things more interesting. Think of Red Stars as exciting "missions" that you have to plan and prepare for in your main star. It is expected most players will participate in at least 4-5 such missions every week in order to advance at a reasonable rate.
The goal of these Red Star missions will be to extract useful resources and jump your ships back to safety before the time runs out. These resources include rare minerals (which require mining fleets to retrieve), and artifacts on planets (which need Transport fleets). There are many obstacles to acquiring those resources, including enemy ships and bases operated by the AI. The exact layout of each star is generated randomly by the game each time someone scans for a Red Star, which hopefully will allow for a lot of variety.
Generally speaking, human players operating in the same Red Star are incentivized to work together. Our design goal for Red Stars is to provide a challenge level that requires most of the participating players to coordinate and work together. However, some adversarial behavior is expected to some degree, given the scarcity of valuable resources and the fact players will not always agree on how they'll share those resources. Still, there will be no direct combat between player ships in Red Stars.
We expect the experience to be very different when playing a Red Star mission with friends vs strangers, and will be monitoring and improving the experience for both types closely. More details will be forthcoming once we have nailed down more details, and are ready to beta test this feature.