What does a star’s red color indicate?

Expert Answers
stolperia eNotes educator| Certified Educator

The color of a star helps to indicate the age of the star by reflecting the type of element that is burning in the nuclear reactions within the star.

A red star is one that has burned all of the hydrogen that was originally contained within its core. Thermonuclear fusion reactions have moved to the shell around the core and are burning the hydrogen contained in that shell by fusing hydrogen atoms into helium, giving off heat and light as a result. The temperature of these reactions is lower than the temperature of a similar reaction located within the core of a star; the lower temperature is the reason for the reddish color.

Further Reading:
aneesh123 | Student

the colour indicate its temperature

astrosonu | Student

Hello! The stars red color indicates the temperature of the star, whether the red part of the star is hot or cold. The red spots in the stars are cooler than the surface of the star.

astrosonuthird | Student

Yes! The blue stars are super hot!!

astrosonuthird | Student

The red color in a star indicates its temperature whether the red part of the star is hot or cold. The red part indicates that the star is cool in that part.

karengettystewart | Student

A star's color is an indication of the star's temperature. A star that is red is at the end of it's life cycle and is about to use up all of it's energy. This can result in a star going supernova. If a star is blue, it is at the beginning of it's life cycle and is extremely hot. When you look at a flame, the hottest part of the fire is at the base, closest to it's energy source. That color is blue, so it is the hottest part of the flame.


If you identify the constellation Orion in the night sky, Betelgeuse is Orion's left shoulder, and is a red star. Scientists hypothesize that this star may have already gone supernova, but since it takes so long (light years) for the light to finally hit the Earth, the source, Betelgeuse, may have already burned out.

The hottest stars are blue and have temperatures of 30,000 to 60,000 K.

Red Stars have temperatures of less than 3,500 K.


chaobas | Student

The colour of the stars reflect the age of the stars. 

Now red indicated that the stars is aged. color is reflected from the fusion reaction it indicated the temperature. if the temperature is high then the star is young. the star will be blue during young stage which indicates high temperature and the nuclear fusion reaction is going on very fast. if it is aged the color intesity will decline till red which shows low temperature due to less fusion reaction.

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