u/GodWithoutAName

Hey everyone!.

I recently picked up a book called Physics of Binary Star Evolution by Thomas M. Taurus and Edward P.J. van den Heuvel. I'm trying to understand binary stars and black holes so I can write a piece of well-informed science fiction.

That said, I immediately came across the problem. Could you tell me what this symbol (the circle with the dot in it) means? Thank you.

For sale. Opened but never used. $25. Ready for pick-up. Address available upon request.