UF :: Astronomy

Coming down a mountain should be easier than going up, but not this time. The storm that assaulted the Roque de los Muchachos mountain top observatories, has rendered any observations impossible through the 10.4 meter GTC telescope. It also has triggered several rock slides along the narrow two-lane road that snakes its way up the side of the ancient volcano. Enormous boulders have completely closed off the road back to Santa Cruz de la Palma.


Two nights of heavy rain and and high winds have further delayed commissioning of the CanariCam. Everything has checked out so far, including the complicated software interfaces with the observatory’s system. All that is need are a few nights of clear skies so that the infrared camera’s performance can be verified. Then it can begin looking deeper into active galactic nuclei hiding supermassive black holes, and debris orbiting young stars in the process of forming their own planetary systems. Today, September 25, it looks like the skies are finally clearing over the island of La Palma.

CanariCam’s intricate optics and electronics are housed within a hexagonal black structure able to withstand the extreme pressure caused by the fact that, although its interior is at a near vacuum, 14.7 pounds per square inch of atmosphere is pressing in.

CanariCam in lab before installation

The interior is also maintained at a temperature of 8-10 Kelvin, just 14.4 degrees Fahrenheit above “absolute zero.” For this reason, astronomers often refer to the camera structure as the “dewar,” a device used for containing and maintaining extremely cold temperatures (essentially a very large and very efficient thermos).

Depending on the mode being used during infrared observations, the optical path from the main telescope may pass through a spectrograph, splitting the electromagnetic radiation and allowing examination of individual spectral lines created by the presence of different elements.

In the polarimetric mode, however, CanariCam can also detect the orientation of radiation that has been polarized through various physical processes. UF astronomer Jonathan Tan, for example, hopes to examine very young stars in the Orion Nebula (M42), a stellar nursery about 1350 light years from us. The stars which have just formed from a collapsing cloud of dust and gas are obscured in visible light by considerable dust, but CanariCam can pierce through and afford a better look. By seeing the actual orientation of this dust caused by enormous magnetic fields, we may be able to better understand the way in which stars and their associated protoplanetary disks form and develop over time.

Uf Astonomer Chris Packham adjusting polarimetric filter for CanariCam installation

CanariCam also has a coronagraph, which basically allows an obscuring disk to be placed in the optical path, allowing the high radiation from bright objects such as stars to be physically blocked out and prevented from overwhelming the fainter surrounding details. The coronagraphic and polarimetric capabilities of CanariCam are unique among the world's mid-infrared instruments.

Many projects are vying for time on CanariCam. Once the camera is successfully commissioned, the largest single telescope in the world will have a new window on the universe. The University of Florida instrument will be only the second one commissioned for this incredible telescope, explaining the keen interest and commitment of the observatory staff to help out every step of the way.

CanariCam installed at focus, with 42 inch GTC secondary mirror assembly visible in upper background

Meanwhile, a lot closer to home, due to the rock slides it is impossible to drive up or down the mountain without a relay of vehicles to assist. I hitched a ride part way down with some astronomers from Durham University in Northern England, who are working on experiments in adaptive optics with another telescope, This technique attempts to eliminate the effects of turbulence in the atmosphere by making minute observations of its effects and adjusting the shape of the telescope mirror in real time to compensate for such fluctuations.

Astronomy is a cooperative international endeavor. Through its partnership with the GTC and through its design and construction of instruments such as Professor Charles Telesco's CanariCam, and Professor Steve Eikenberry's FLAMINGOS-2 (a near-infrared wide field imager with multi-object spectrographic capabilities, installed at Gemini South Observatory, Chile), the University of Florida stands shoulder to shoulder with astronomers from around the world, putting Gators at the forefront of new scientific discoveries.

These blogs were written by Terry Smiljanich, a member of the Advisory Council of the UF Department of Astronomy, and will continue next week with updates on the continued commissioning and performance of CanariCam.