 U Equulei is, or was, an OH/IR star, and strong OH and H2O masers have been observed.These vary to a greater extent than almost any other star observed, and it is possible that the stage of maser activity is essentially finished.Lionel Siess and Mario Livio suggested that the accretion of a giant planet towards the increasing red giant has made the star's outer layers rotate fast enough to cause an outpouring equatorial- or disk-expansion, responsible for the star's peculiar environment.