Surprise! The biggest and most massive stars aren’t always the hottest.
To first become a star, your core must exceed a critical temperature threshold: ~4,000,000 K.
These temperatures are required to initiate the primary fusion of hydrogen into helium.
However, the surrounding layers diffuse heat, limiting photospheric temperatures at around 50,000 K.
Higher temperatures require additional evolutionary steps.
Your star’s core contracts and gets hotter when the hydrogen is exhausted.
Then helium fusion begins, pumping out more energy.
However, “red giant” stars are very cold, and they expand to reduce their surface temperatures.
Most red giants blast their outer layers away, revealing a hot, contracting core.
With surfaces of white dwarfs up to 150,000 K, they outperform even blue giants.
However, the highest stellar temperatures are achieved by Wolf-Rayet stars.
Wolf-Rayet stars are heading for cataclysmic supernovae, fusing heavier elements.
It is highly developed, luminous, and enclosed in a shell.
The hottest measures ~210,000 K; The main “real” star.
The remaining cores of supernovae can form neutron stars: the hottest things ever.
With initial internal temperatures of about 1 trillion K, they rapidly radiate heat.
After a few years, their surfaces have cooled to 600,000 K.
Despite everything we’ve discovered, neutron stars remain the hottest and most dense objects devoid of singularity.
Mostly Mute Monday tells an astronomical story with pictures, visuals, and no more than 200 words. taciturn; smile more.