What Distinguishes a Star from a Quasar?
Question:
So my friend was on his telescope and was taking pictures and he found what seemed to be a quasar but we dont know. It looks like one but we cant confirm or deny, what do we do?
Answer:
With even the larger optical telescopes that astronomers have at their disposal, one cannot tell the difference between a star and a quasar as they both look like bright points of light in an image made with an optical telescope. The name “quasar”, in fact, means “quasi-stellar radio source”. It is only when you measure the intensity of the light that a quasar produces that you find that it looks different from a star’s light. Quasars are largely found to be located very far away from us. This causes the light emitted by atoms in a quasar to be redshifted relative to the normal wavelength that we would expect to see emission from atoms. This redshifted light from atoms, in fact, is how quasars were finally explained as very distant galaxies.
