"Only good thing my family taught me," he manages. Sirius points. "I’m there. Sirius. The Dog Star." Immediately, out of habit, his eyes wander to find Regulus. He doesn’t point it out. He hasn’t pointed Regulus out since fourth year, when he decided on a foolish impulse that ignoring the star meant ignoring his brother—a move that only served to lower his Astronomy grade and convince himself further that Regulus could not and did not want to be saved by him. He’s still not entirely sure what happened to Reg, in the end.