Spectrometry Flashcards
What is a spectrum?
The range of colours between red and violet obtained when white light is split up using a prism.
Why do light spectra from stars and galaxies contain dark lines and what is this pattern called?
Absorption spectra.
Caused by light at these wavelengths being absorbed by the suns atmosphere and sometimes the earths atmosphere.
What is emitted from the sun?
A mixture of different coloured light which forms a spectrum.
What does absorption spectra tells us and how?
What element the star or galaxy is made out of. Each element has it’s own unique absorption spectra so spectrometers can identify which element it is.
When the waves collide, they are sent off in every direction, so by the time they reach earth they are so weak we view them as black within our spectrometers.
Why do some spectra’s have bright lines and what are they called?
Emission spectra is caused by extra light being emitted at these wavelengths.
What does emission spectra tell us?
What a star or galaxy is made of.
What is a spectrometer?
An instrument that can split up light to show the colours (wavelengths) of the spectrum. They are used to analyse the light given out by stars and galaxies.
How do spectrometers work within large optical telescopes?
The telescope directs a beam of light into the spectrometer and through a slit. This diffracts the light and splits it up into a spectrum.
Visible light is…..
A mixture of light with different wavelengths and frequencies.
What can the visible light be split up with?
A prism or something that has lots of lines on it.
What colour does the spectra of galaxies far away appear to be?
Red
