a star having a diameter of from 10 to 100 times that of the sun, as Arcturus or Aldebaran.
Compare supergiant star.
Origin of giant star
First recorded in 1910–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any of a class of stars, such as Capella and Arcturus, that have swelled and brightened considerably as they approach the end of their life, their energy supply having changedSometimes shortened to: giant Compare supergiant
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
A very large, bright non-main-sequence star that burns hydrogen at a much faster rate than a dwarf star. Giant stars are much more luminous and have shorter lifespans than the slower-burning dwarfs. The larger the giant, the shorter its lifespan; the largest stars, with solar mass of around 100, blaze at several hundred thousand times the energy of the Sun and will last only a few million years, a very brief time when compared with the Sun's 10-billion-year lifespan. Giant stars usually end their lives as supernovae , but even before that event the immense ultraviolet radiation they produce has a dramatic impact on their stellar surroundings; the presence of a giant star in a star system prevents the formation of new protostars because the radiation from the giant star breaks apart any nearby nebulae.
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