Who coined the terms giant and dwarf for stars in 1905 or 1906?
Ejnar Hertzsprung coined the terms giant and dwarf in 1905 or 1906 to describe stars with vastly different luminosities despite sharing similar surface temperatures.
Questions about Giant star
Short answers, pulled from the story.
What defines a giant star radius compared to our Sun?
A giant star possesses a radius up to several hundred times that of our Sun while emitting over ten times more light than the Sun itself.
When does a star transform into a giant after exhausting hydrogen fuel?
A star transforms into a giant only after exhausting all hydrogen fuel available for fusion within its core, causing the core to contract and heat until hydrogen begins fusing in a shell surrounding it.
Which spectral classes define red giants like Pollux and Arcturus?
Red giants represent the most common type of giant star due to their moderate mass and relatively long stable lifespans, with cooler spectral classes K, M, S, and C defining these stars which appear prominently on Hertzsprung, Russell diagrams after the main sequence.
How do intermediate-mass stars above roughly 0.25 solar masses evolve from subgiants?
For intermediate-mass stars above roughly 0.25 solar masses, the outer layers expand and cool while luminosity increases only slightly during this phase which marks the transition from a subgiant to a red-giant branch where the star burns hydrogen steadily for about 10% of its total life.