Observing with UKIRT

Here is a short time-lapse of UKIRT in action!

UKIDSS - the UKIRT infrared deep sky survey

I am currently at 4,200m, at the summit of Mauna Kea in Hawaii, using UKIRT - the United Kingdom's Infra-Red Telescope. We are using UKIRT to carry out the UKIDSS - the UKIRT Infra-red Deep Sky Survey.

Actually, UKIDSS is not one survey, but five similar surveys which will take 7 years to complete! The five surveys are:

• Large Area Survey (orange in the all-sky map below)
• Galactic Plane Survey (purple)
• Galactic Clusters Survey (green circles)
• Deep Extragalactic Survey (blue squares)
• Ultra Deep Survey (red dot within the blue square)

Both the Large Area Survey and the Ultra Deep Survey are looking for very distant galaxies (cities of stars). By "Ultra Deep", astronomers mean "ultra-sensitive", and so the Ultra Deep Survey will be able to detect very faint and very distant galaxies.

Running five surveys in parallel makes it a very efficient survey - if one of the surveys cannot be done on a particular night, another one can be done instead. For example, it may be slightly hazy as it is as I type this, which would mean that we cannot see the very faint galaxies that the Ultra-Deep Survey is looking for, but we can look at the star-filled galactic plane instead, which is easy to see through haze.

For the galactic plane survey, exposures are only 14 minutes long; for the ultra deep field, exposures are 75 minutes long!

Being an Astronomer

There are about 10,000 astronomers around the world - but what do they do?!

Astronomers are usually based at a university, and they often spend some of their time teaching. But when the students are away they get time to do some 'proper work' - their research. This is especially true during the summer holidays!

Maybe once a year (or more, if they are lucky), an astronomer gets the chance to use a world-class telescope, either on-the-ground or in space.

I've been lucky enough to get time on the UK Infra-Red Telescope (UKIRT), one of the British telescopes based in Hawaii. On the 31st of August, I set off on the very long journey... London to Los Angeles (11 hours!), catching another plane a few hours later to Honolulu (a 6 hour journey), staying overnight in a hotel before finally catching an early-morning short flight (1 hour) to Hawaii's big island - from where I took the photograph of the summit below.

After a day (trying) to recuperate (the spare day also being useful in case I missed a connecting flight), I headed to the Joint Astronomy Centre in the coastal town of Hilo for a debriefing of how to use the telescope, and to discuss any issues. A lot of this time was spent discussing the health and safety issues. We are working nights, with heavy equipment, at 4,200m - this incredible altitude (almost half-way up Mount Everest!) makes altitude sickness a real and ever-present danger.

I then travelled from sea-level, half way up to the summit to Hale Pohaku - the astronomers and support staff hotel. While it is some way from the telescopes, it is considered to be a safe altitude, at only 2800m.

More about what we are actually observing in another post...!