www.galaxies.se - by Ivar Hamberg

Rasalgethi, Alpha Herculis: 

This is a 60 sec spectrum of alpha Herculis. It is a multiple star system. The strongest star is denoted A1 and is dominating this spectrum. The star is classified as an M5 type star, placed on the Asymptotic Giant Branch (AGB).  It is a pulsating variable star, somewhat similar to Mira in Cetus.

The spectrum is totally dominated by molecular TiO bands, although several other elements can be seen. This colorful sawtooth appearance is very typical of an M star, and quite prominent here in this raw spectrum presentation. (This spectrum curve is only dark field corrected.)

Some terrestrial absorption lines are also seen.

(Details to follow at later time.)