Needless to say, this description will involve spoilers.
I recall reading a science fiction short story about a female grad student. Her colleague is in LEO on a space station when a solar flare kills him. The work he leaves behind hints that something is strange about the class of stars the two were investigating before his death. They're studying a sort of dwarf star, and they were trying to figure out how they could be formed. I don't remember why exactly their formation was mysterious.
Later, the grad student is driving to the base of a space elevator located at the top of a mountain. Despite being warned that a heavy snowstorm is approaching, she continues on. She crashes to the side of the road and realizes that without shelter, she'll be in trouble. She knows there is an emergency cabin on the side of the road for this purpose, and heads for it. Just before succumbing to the cold, she sees the red siren light left for just this purpose pulsing in the window of the cabin, and makes it inside safely.
The siren which guided her into the cabin gives her an idea. She discovers that the dwarf stars have an uncharacteristic amount of some radioactive element – I don't remember which one. The big reveal, in a meeting with senior faculty, is that the dwarf stars are artificial, placed there by unknown actors, as lighthouses to warn others away from nearby black holes. She proves this by pointing out that each anomalous star has a black hole near it, each star has the same, unusual amount of radioactive material (she reasons that radiation is a universal symbol for danger), and finally by identifying two more stars that are under construction! Then the story ends.
That's all I remember. Ring any bells?