red giants
Large cool stars are classified as K-type and M-type stars. K-type stars are orange in color and have surface temperatures ranging from about 3,700 to 5,200 Kelvin, while M-type stars are red and have temperatures below 3,700 Kelvin. These stars are generally larger than the Sun and can be found on the cooler end of the main sequence in the Hertzsprung-Russell diagram.
Red giants.
Large, cool, and bright stars are typically classified as red giants. These stars have expanded and cooled after exhausting the hydrogen fuel in their cores, leading to their large size and reddish hue. Red giants are often in a later stage of stellar evolution, and they can be significantly more luminous than smaller, cooler stars. Examples include Betelgeuse and Aldebaran.
Red supergiant stars, such as Betelgeuse and Antares, are examples of stars that are very cool in temperature while still being extremely luminous due to their large size and high brightness. Despite their cool surface temperatures, they radiate a tremendous amount of energy into space.
The large, cool stars found at the upper right of the H-R diagram are red giants. These stars are in a later stage of their evolution, where they have exhausted their core hydrogen fuel and expanded in size. They are cooler in temperature but have a large luminosity due to their increased surface area.
Large cool stars are classified as K-type and M-type stars. K-type stars are orange in color and have surface temperatures ranging from about 3,700 to 5,200 Kelvin, while M-type stars are red and have temperatures below 3,700 Kelvin. These stars are generally larger than the Sun and can be found on the cooler end of the main sequence in the Hertzsprung-Russell diagram.
Red giants.
To be bright you need to be hot, close or have a large surface area. The brightest coolest stars are red super giants. They have such a large surface area, that even though their surface temperature is cool - in star terms - their large surface area makes them appear bright.
They are either small and cool and fusing hydrogen or large and hot, fusing helium. The large and hot ones ape read because although they are hot, this heat is radiated over a large surface area. Large red stars are approaching the end of their lives, small, cool red stars will have very, very long lives.
Large, cool, and bright stars are typically classified as red giants. These stars have expanded and cooled after exhausting the hydrogen fuel in their cores, leading to their large size and reddish hue. Red giants are often in a later stage of stellar evolution, and they can be significantly more luminous than smaller, cooler stars. Examples include Betelgeuse and Aldebaran.
Madalynne Braseltonstellar classification is the classification of stars based on their spectral characteristics
Red supergiant stars, such as Betelgeuse and Antares, are examples of stars that are very cool in temperature while still being extremely luminous due to their large size and high brightness. Despite their cool surface temperatures, they radiate a tremendous amount of energy into space.
The large, cool stars found at the upper right of the H-R diagram are red giants. These stars are in a later stage of their evolution, where they have exhausted their core hydrogen fuel and expanded in size. They are cooler in temperature but have a large luminosity due to their increased surface area.
The red giant galaxies are large non-main sequence star of stellar classification. These are classified K or M because of the reddish appearance of the cooler giant stars.
Small cool stars, such as red dwarfs, are typically red or orange in color. This is because their surface temperatures are relatively low, causing them to emit more red and orange light compared to other colors.
A very cool one!
cool