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

Stellar size and class diversification originates from the initial mass of the molecular cloud from which stars form. The elemental composition of the molecular cloud, specifically the abundance of ...

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 ...