ABOUT ALDERAMIN

Alpha Cepheus

Alderamin [1] is an A-type star [2] (white star in the main sequence) located about 49 light years from Earth. It is a star at the end of its life which should evolve into a subgiant and then into a red supergiant. Twice as massive as the Sun, 17 times more luminous, its volume is 12 times that of our star. It rotates on itself in less than 12 hours (compared to almost a month for the Sun), which suggests very intense magnetic activity. This type of star has a shorter lifespan compared to that of the Sun. Alderamin will be the visible star closest to the North Celestial Pole around the year 7500, thus becoming our new North Star [3]!

[1] ‘Alderamin’ means ‘the right arm’ (of the King) in Arabic.

[2] The different spectral types (OBAFGKM) extend
cold M-type stars (2,000 K for the coldest)
to very hot O-type stars (up to 50,000 K).

[3] It already occupied this place 20,000 years ago.