What Do The Spectral Class Letters Stand For? The full order of classification is O, B, A, F, G, K, M – more easily remembered by using the mnemonic “Oh Be A Fine Girl/Guy, Kiss Me”. This also orders adult (main sequence) stars from hot to cool; the hottest (and largest) main sequence stars are
Who Developed The Spectral Classification System For Stars? The scheme in use today is the Harvard spectral classification scheme which was developed at Harvard college observatory in the late 1800s, and refined to its present incarnation by Annie Jump Cannon for publication in 1924. Who created the classification system for stars that uses o’b a
When Did Helen Sawyer Hogg Die? Helen Hogg continued to work for free until she was offered a position as a research assistant in 1936. As Hogg’s professional career grew, so too did her family. In 1936 she gave birth to son David and in 1937 James was born. Hogg continued her professional activities even