March 25, 2004

a cold night in the observatory


Setting off at 10 pm we walked the 5 minutes or so to the observatory through a warren of buildings, heads cricked to the heavens. The night was freezing and clear, perfect weather to visit the telescope.

I was hoping for a glimpse of Jupiter, which we'd spied above us on the walk, but first we had to align the telescope. This meant pointing it at certain highly visible stars of known coordinates and synchronising its computer control - so that we could then find objects invisible to the naked eye, simply by typing in their location.

The first star targeted was Capella. The telescope records what it sees as a digital image but there is a small optical telescope attached to help roughly align it. Seen through it the star assumed a physicality previously lacking. Not exactly 3D but an exagerated 2D, a new spherical clarity, floating against a background of previously unseen stars.

Captured in the optical telescope its image was brought up on the screen and the telescopes orientation fine tuned until the star glowed in the dead centre of the monitor.

A time consuming business, and a chilly one, under the open dome of the telescope, the cold air falling in. The procedure was repeated for Polaris and now ready for serious observation, the telescope was cooled down to -25 degrees centigrade ( to improve its focus ) and the coordinates of the nights objective typed in, GRC 188.

Viewed through the optical telescope there lay a field of stars, 5000 light years away.

Chilled to the bone, colder than a supercooled lens, I left my companions to their observation as they fine tuned the focus to take a pristine 100 second exposure. I never did get to see Jupiter.

Posted by Jem Finer at March 25, 2004 4:42 PM