Red giants.
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.
Large cool stars are classified as either K or M type stars on the spectral classification scale, with M stars being cooler and redder than K stars. These stars are part of the main sequence on the Hertzsprung-Russell diagram and have surface temperatures lower than 5,000 K.
Cool red giant stars are located in the upper right corner of the Hertzsprung-Russell diagram, where they are both cool (low temperature) and bright (high luminosity). These stars have evolved from main sequence stars and are in a late stage of stellar evolution.
Our sun is a typical star compared to others in the universe. It is a G-type main-sequence star, similar in size, age, and composition to many other stars. It is not particularly large or small, hot or cool, bright or dim in comparison to the billions of stars in the galaxy.
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.
Hot stars are found in the left hand side of the diagram, cool stars the right, bright stars at the top, and lastly the faint stars are located at the bottom.
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.
the ones in the sky
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.
top,right
Large cool stars are classified as either K or M type stars on the spectral classification scale, with M stars being cooler and redder than K stars. These stars are part of the main sequence on the Hertzsprung-Russell diagram and have surface temperatures lower than 5,000 K.
The red giants like Betelgeuse and Antares are bright and - relatively - cool.
The red giants like Betelgeuse and Antares are bright and - relatively - cool.
The red giants like Betelgeuse and Antares are bright and - relatively - cool.
Cool red giant stars are located in the upper right corner of the Hertzsprung-Russell diagram, where they are both cool (low temperature) and bright (high luminosity). These stars have evolved from main sequence stars and are in a late stage of stellar evolution.