Alpha Cephei, also named Alderamin, is a second magnitude star in the constellation of Cepheus near the northern pole.

Aldermain will next be the North Star in about the year 7500 AD.

Alderamin has a very high rotation speed of at least 246 km/s, completing one complete revolution in less than 12 hours, with such a rapid turnover appearing to inhibit the differentiation of chemical elements usually seen in such stars.

The star is relatively close to Earth at 49 light years. With a declination in excess of 62 degrees north, Alderamin is mostly visible to observers in the northern hemisphere, though the star is still visible to latitudes as far south as −27\xb0, albeit just above the horizon. The star is circumpolar throughout all of Europe, northern Asia, Canada. Since Alderamin has an apparent magnitude of about 2.5, the star is easily observable to the naked eye, even in light-polluted cities.