how do we produce a spectrum?

A raindrop is nature's way of producing a spectrum. Check out the Factary entry for rainbow to see some querky facts about rainbows. In laboratory experiments we can use a glass prism to split light into different wavelengths (colours), as in the picture below.

To study the light from the Sun in detail, we use an instrument called a spectrometer. Light enters the spectrometer from a telescope and is then split up into its different wavelengths. I use the Coronal Diagnostic Spectrometer (CDS) on board the SOHO spacecraft to produce the spectra I work with.

Beyond the violet end of the spectrum is the ultraviolet (UV). CDS splits the Sun's UV radiation into its individual wavelengths so I can see the details of the emission spectrum - the Sun's ultraviolet fingerprints.

For me, the exciting thing is that these emission lines in the UV part of the spectrum can tell me a lot about the makeup of the Sun

For many people, the most important thing about UV radiation is that too much of it can make fair skin darken or even burn. That's why we need to be very careful and cover up with clothes or sunblock lotion. Fortunately, the Earth's atmosphere filters out a lot of the Sun's harmful UV radiation - that's why we need to go up into space to study it with SOHO!