New spectroscopic evidence that H2 molecules present in the gaseous atmospheres of OB stars displaying the 2175A "Bump" are coherently photoexcited

Archived VUV spectra of OB stars with the 2175A "bump" contain several "extra" narrow absorption bands fully explainable by H2 four-wave mixing, providing new evidence for the H2 nonlinear optics model we recently proposed. © 2008 Optical Society of America.