This honestly sounds like it's basically impossible, but here we go anyway.
We've picked up a strange reading from a spot orbiting a star in a system elsewhere in the Milky Way galaxy. We've come into orbit nearby, and decided to investigate in person. We suit up, head out with our self-propelled space backpacks and, oddly enough, our systems indicate that we can safely remove our helmets. Here? In open space? With no planet or even a large asteroid anywhere remotely nearby? How could this be possible?
Well, I suppose that means that, despite near-impossibly slim probability, this star...
- Has some sort of gas cloud orbiting it right where we happen to be, and among the gasses are just the right gasses in the right proportions and pressures for humans to breathe and also nothing fatal. Maybe a circumstellar ring? Permissibly, there can be lots of space junk also in proximity.
- Is of an appropriate size, temperature, radiation level, etc to have a region that is the right temperature, pressure, etc for us to survive.
- Probably many other factors we aren't even considering.
Could such an environment really exist? We don't need to survive long-term; we can go back to the ship for water, food, etc. We would just like to be able to remove our helmets in this unusual place. What would have to happen for this to exist?
Bonus points if we can safely look at the star with the naked eye, and super bonus points if it can actually occupy a significant arc of the "sky."