Program: GS-2007A-C-2

We propose to record high-resolution spectra of the FeH 1.58 micron band for several M and L dwarfs. The target late-type M dwarfs have known magnetic activity. FeH shows significant Zeeman effect. This program will be the first high-resolution use of the molecular Zeeman effect in the infrared to probe magnetic activity in stars other than the sun. If as successful as we expect, this technique will expedite the exploration of magnetic activity in the very coolest dwarfs. In the coolest dwarfs few atomic lines are present and these lines are not good probes of magnetic activity. Magnetic activity is expected in the very cool dwarfs.