Ultraviolet Light
Electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. Ultraviolet observations are crucial for studying hot astronomical objects like accretion disks around black holes.
Source: science.nasa.gov
APODs including "Ultraviolet Light"
Starburst Galaxy M94
16/10/1995
The spiral galaxy M94 is somewhat unusual in that it shows a great ring of bright young stars particularly apparent when observed in ultraviolet light, as shown above. Such a high abundance of these young blue stars may cause a galaxy to be designated a starburst galaxy. It is likely that many of the stars seen in the above ring were created when a density wave moving in the galaxy compressed existing galactic gas. The above picture was taken by the Ultraviolet Imaging Telescope during the Astro-2 mission in March 1995.