The HOU images used for these activities were taken in sets of three. For each set, images were taken with a red, green and then a blue filter on the telescope. The purpose of using filters is to be able to compare the amount of starlight which passes through each filter. By comparing the amount of starlight getting through each color filter, astronomers analyze the color of the light coming from the stars. However, some stars are cooler or hotter than other stars.
Hotter stars shine in the bluish areas of the spectrum.
You will compare three images of a mystery star. Each image was taken with a different color filter. You will compare the brightness of the mystery star in each of the three images. The star will look brightest in the image which was taken with a filter that is most like the color of the light coming from that star. You will compare three images of the stars of the Orion Nebula, M42.