Alpha Cassiopeiae (α Cas, α Cassiopeiae ) is a second magnitude star in the constellation Cassiopeia, with the traditional name Schedar, sometimes spelt Shedir. Though listed as the alpha star by Johann Bayer, Schedar's visual brightness closely rivals the beta star in the constellation, Caph. Depending on which passband is used, α Cas may be marginally brighter or dimmer than β Cas. However, recent calculations from the All-Sky catalog indicate that Schedar is the brightest in Cassiopeia, with a visual magnitude of 2.240. With Schedar located farther away from Earth than Caph, at 228 light years versus 54, Schedar is almost 18 times brighter than its rival insofar as intrinsic brightness is concerned.

Shedir has been scanned before.