This diagram shows the spectral types of all stars within 34 ly in this area all the stars are known, which is why it is often used for the spectral types projections in our galaxy. Astronomers believe that most of the stars are small M dwarfs, which are also represented in this diagram by far the most common.
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Positive can point out that there are no massive O and B stars are in our neighborhood. These stars have only a (relatively) short life, ending up in a supernova. Such a supernova explosion would have disastrous consequences for life on Earth.