Alan Marscher knows he can’t be a star. Well, astronomically speaking. But that’s not stopping the Boston University astronomer from writing and singing songs like “Superluminal Lover” and another about a black hole with the lyrics “Attracted by your gravity, your body’s so compact. Pulling me inward, prepare for close contact.” Of course it’s no worse than “I am, I said. To no one there. And no one heard at all, Not even the chair” or “I don’t like cities, But I like New York. Other places make me feel like a dork.” So maybe he should start using only his first name, Alan, and get Justin Timberlake to produce his next album. Sales could be, uh, astronomic.