How to use a spectrometer to measure the temperature of stars & their gases?

Question

anonymous · Answer

by classical theory, higher temp ->implies-> higher energy radiation
by plank's theory, this radiation is discreet and dependent on temperature. These discreet particle, called photos, will have a wavelength corresponding to that energy.
This can be observed as a strong color in the spectrometer and the temperature of the region of space if estimated.

anonymous · Answer

A spectrometer measures the different intensities(for different wavelengths in the spectrum), and based on that you can calculate the bolometric or total intensity which would then give you the 'Effective Temperature'. Effective temperature is the temperature with which a blackbody would radiate at the same bolometric intensity.  We treat this temperature as the surface temperature of the star.