Vulcan

LORELAI: Well, I don’t know exactly what’s going on in Rachel’s head because I’m not a Vulcan, but from the way she talks about you and the way she smiles when your name comes up, I’m pretty sure that she’s serious about staying in Stars Hollow this time.

Vulcans are an alien species in the Star Trek universe, from the plant Vulcan. Noted for their logic and reason, they were the first alien species to make contact with human beings. Many Vulcans are telepaths, and can perform a “Vulcan mind meld” to read someone’s mind, which explains Lorelai’s comment.