if the spectrum of a star indicates that the star shines with a red light, approximately what is the surface temperature of the star?

http://en.wikipedia.org/wiki/Color_temperature

To determine the approximate surface temperature of a star based on its spectrum, we can refer to the concept of stellar classification. Stellar classification is a system that categorizes stars based on their spectral characteristics, including their temperature.

In the case of red light emission, we can infer that the star belongs to the coolest spectral type, known as M-type stars. These stars have surface temperatures ranging from approximately 2,400 to 3,700 Kelvin (K). However, the exact temperature within this range depends on the specific spectral lines and absorption features present in the star's spectrum.

To obtain a more accurate estimate, one must analyze the detailed spectral profile of the star and compare it with a spectral atlas or database. The analysis involves identifying characteristic absorption and emission lines, evaluating their relative strengths, and comparing them with known spectral types to determine the temperature.

Therefore, to pinpoint the exact surface temperature of the star shining with red light, a more comprehensive analysis of its spectrum would be necessary, comparing it to the known spectral types and their respective temperature ranges.