Variable stars are popular targets for amateur astronomers, their observations providing valuable contributions to understanding star behaviour. Located near Alkes is the red-hued R Crateris, a semiregular variable star of type SRb and a spectral classification of M7. It ranges from magnitude 9.8 to 11.2 over an optical period of 160 days. It is 770 ± 40 light-years distant from the Sun. TT Crateris is a cataclysmic variable; a binary system composed of a white dwarf around as massive as the Sun in close orbit with an orange dwarf of spectral type K5V. The two orbit each other every 6 hours 26 minutes. The white dwarf strips matter off its companion, forming an accretion disk which periodically ignites and erupts. The star system has a magnitude of 15.9 when quiescent, brightening to 12.7 in outburst. SZ Crateris is a magnitude 8.5 BY Draconis type variable star. It is a nearby star system located about 42.9 ± 1.0 light-years from the Sun, and is a member of the Ursa Major Moving Group.