The GTC shutter

GTC Shutter
July 30, 2014

  GTC has been open for five years, and the massive dome shutter has been getting some maintenance. This photo give an idea of the sheer size of the dome shutter.


Happy Birthday to Gran Telescopio Canarias

GTC at sunset, Roque de Los Muchachos, La Palma
July 25, 2012

Gran Telescopio Canarias (Big Canarian Telescope) also known as GranTeCan or GTC was inaugurated on July 24th 2009. It’s the largest optical an infrared telescope in the world, with a segmented main mirror 10.4 m acros which gathers as much light as four million human eyes. The top of the dome is 41 m above the ground. GTC is owned 5% by the university of Mexico, 5% by the university…


Realuminizing GTC’s tertiary mirror

The light path on a KECK telescope
June 29, 2012

  Modern telescopes have mirrors made of a material called vitro ceramic, which keeps its size and shape in spite of changes in temperature, covered with a very thin layer of aluminium. Domestic mirrors have glass in front of the aluminium, to protect it, but that means that the light passes through the glass twice – coming and going – which degrades the image. So telescope mirrors have the aluminium…


The Observatory

Gran Telescopio Canarias, or GTC, the biggest optical telescope in the world, Roque de Los Muchachos observatory, La Palma
February 10, 2008

  Twinkling stars are pretty, but astronomers would much rather they didn’t. The twinkle is caused by movement in the air above you (the same as a mirage on very hot days) and it stops the astronomers getting a clear view. The Hubble Telescope gets such wonderfully clear images because it’s out of the atmosphere altogether. But there’s only one Hubble, and it cost a fortune. So they build ground-based…