RY Ursae Majoris
RY UMa is a semiregular variable of type SRa, meaning it has reasonably stable pulsations over part of its history, but with lower amplitude than their Mira-type cousins. In this case, RY UMa has a well-defined pulsation period around 310 days, but it also has a supercycle of several thousand days during which the pulsations apparently cease. It's not clear why this is the case. RY is a bright variable for the northern hemisphere, well within range of most observers including binocular observers.