We report a multi-week sequence of B-band photometric measurements of the dwarf planet Eris using the {it Swift} satellite. The use of an observatory in low-Earth orbit provides better temporal sampling than is available with a ground-based telescope. We find no compelling evidence for an unusually slow rotation period of multiple days, as has been suggested previously. A $sim$1.08 day rotation period is marginally detected at a modest level of statistical confidence ($sim$97%). Analysis of the combination of the $Swift$ data with the ground-based B-band measurements of citet{2007AJ....133...26R} returns the same period ($sim$1.08 day) at a slightly higher statistical confidence ($sim$99%).
Download