Abstract

LS I +61 303 is an exceptionally rare example of a high mass X-ray and gamma-ray binary, consisting of a Be star and a probable neutron star companion. The Be circumstellar disk interacts with the companion to produce emission that has been observed to vary at every wavelength across the electromagnetic spectrum, from radio to TeV, over both the 26.5-day orbital period and a longer 1667-day superorbital period. Here we present new KPNO Coude Feed spectra of the disk emission to study its variability over both timescales. We also investigate the Fermi lightcurve of LS I +61 303 to find that the GeV variability is closely related to the H$alpha$ behavior. We gratefully acknowledge support from the National Science Foundation through the grant AST-1109247 and REU site grant PHY-0849416.