1.   Sunlight delivers both so-called burning rays, the UV-B part of the ultraviolet spectrum, and tanning rays, the UV-A part of the spectrum.

2.   The Hubble Space Telescope has a similar but less powerful capability to scan the ultraviolet spectrum, which these observations will complement.

3.   These lines would appear in a part of the ultraviolet spectrum that is blocked by air and so cannot be seen from the ground.

4.   But Davidsen and others believed that a telescope looking in the far ultraviolet spectrum from space could detect at least part of the elusive gas.

5.   Patients bathe in the mineral- and salt-rich waters and then sunbathe under the natural ultraviolet spectrum of light.