Why is light used in astronomy?

Answer 1

The most common way is to do a spectral analysis. EM radiation arrives right across the spectrum of different frequencies, and a lot of information is discovered by recording and analysing the different amounts that arrive at the different frequencies.

One of the major methods used is to identify different elements in parts of the universe by their spectral lines - energy concentrated at certain frequencies/wavelengths.

Answer 2

It is important for astronomers to study the entire range of the electromagnetic spectrum because every star, including our Sun, emits light at a wide range of wavelengths, all across the visible spectrum, and even outside the visible spectrum. Astronomers can learn a lot from studying the details of the spectrum of light from a star.

Answer 3

For very much the same reason that a musician studies sound. Because that's the mode by which information can be gathered regarding the objects and processes that the astronomer is really studying. And don't forget radio too.

Answer 4

Telescopes use light created by the stars in order to either refract it or reflect its image in the hope of magnifying the image.

Answer 5

I believe you are referring to a field known as spectroscopy, wherein the light reflected from a celestial body is measured to reveal the composition of that object based on wavelengths.

Answer 6

Because of how far away everything is in the galaxy.

Answer 7

they study the colour because that tells you how hot or cold it is

Answer 8

We use astronomy my because of our urge for curiosity and exploration, to understand the universe around us which can also help understand our own planet.