© Julien Girard 2011 www.djulik.com
This is a 30-minute exposure taken on July 21, 2011 while I was actually supporting observations on UT4. I was observing an ultraluminous Infrared galaxy that hosts an active galactic nucleus (AGN) in it's core. This was done in service mode using the imager NACO and the Laser Guide Star Facility feeding its adaptive optics system. I quickly setup my camera on a fixed tripod while the laser was first being propagated and focused and a quickly ran back in the control building to take the scientific data.
The four VLT/UTs and VST are visible as well as the VLTI control building. The star tracks due to the earth rotation show their colors (red to blue). The yellow laser plume corresponds to the rayleigh scattering of the light by atmospheric particle in the first few km. The artificial star created at about 90 km altitude is too faint to appear in such image.