A Breathtaking Window on the Universe: A guide to the observatory at the Roque de Los Muchachos
Today I sent my book off to the printers. It should be on sale in 3-4 weeks.
telescopes
Happy Birthday to Gran Telescopio Canarias
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
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…
Photographing GTC’s tertiary mirror
Yesterday the maintenance team took the tertiary mirror out of the huge GranTeCan telescope, and I was invited to take photos. (Starlight hits the huge primary mirror first, then bounces up to the smaller secondary mirror at the top of the telescope, then back down into a tube called the baffle to the flat tertiary at 45º, which sends it to the scientific instruments at the sides. The tertiary is elliptical, and…
A birthday present for the William Herschel Telescope
The William Herschel Telescope is 25 years old today – first light was the 1st June 1987. For many years the Herschel was the biggest optical and infrared telescope in Europe, until Gran Telescopio Canarias opened in 2009. It’s main mirror is 4.2 m or 165? across which was huge when it opened, although that’s medium-sized these days. The telescope has so many different instruments that it’s been compared…
Inside the HARPS-N spectrograph
Francesco Pepe invited me to see inside the HARPS spectrograph. I was very lucky, because the enclosure was closed for the inauguration, and closed again (probably for years) soon after I took these photos. Of course I had to wear special over-clothes to prevent dust getting into the instrument. The top photo shows the grating, which splits the starlight into a rainbow, and the bottom one shows the collimator,…