Stars are grouped according to their spectral characteristics by single letters of the alphabet, optionally with numeric subdivisions.

The seven main types of stars. How they’re classified and their roles in stellar evolution, lifecycle stages, and how they appear in the night sky.

Dec 18, 2025 · Scientists call a star that is fusing hydrogen to helium in its core a main sequence star. Main sequence stars make up around 90% of the universe’s stellar population. They range in …

Star classification chart & guide. Learn about all the main star types and their characteristics, including life cycle, mass, size, luminosity, temperature.

This diagram shows most of the major types of stars. The vast majority of stars are main sequence stars - these are star like the Sun that are burning hydrogen into helium to produce their energy.

Dec 4, 2025 · From hot stars to cool, the order of stellar types is: O, B, A, F, G, K, M. (A traditional mnemonic for this sequence is “Oh Be A Fine Girl [or Guy], Kiss Me.”) Additional letters have been …

In astronomy, stars are classified based on their spectra. Different types of stars (listed below) have different spectral characteristics and, even though they only differ in brightness to the unaided eye, …

There are many types, like red dwarfs to hypergiants. Each star type is unique, with its size, brightness, and life cycle. In astronomy, stars are sorted into seven main groups: O, B, A, F, G, K, and M. This …

May 3, 2025 · To understand stars is to understand the universe itself. This article takes you deep into the heart of stellar science — from the birth of a star in vast clouds of gas and dust, to its dramatic …

Jan 28, 2009 · In truth, stars are about as diverse as anything else in our Universe, falling into one of many different classifications based on its defining characteristics. All in all, there are many...