What is the origin of the letters used in star classification? Why didn't astronomers use ABCD? J. HaldimanChicago, Illinois ...

To understand how we classify and differentiate the stars we see in the sky, we first need to understand how they are born and change throughout their lives. Star formation begins with a massive cloud ...

Stellar spectral types originally followed alphabetical order. But as astronomers observed more stars and obtained more detailed spectra, they consolidated some categories and reordered the remaining ...

Stellar spectral types were initially arranged alphabetically; however, subsequent detailed observations led to the consolidation and reordering of categories, establishing the current OBAFGKM ...