XMM-Newton: 10 years old today!

The XMM-Newton space telescope is celebrating its 10th anniversary in space!

Although there is a huge amount of British involvement in XMM-Newton, it truly is an international mission. In brief...

• Two out of three X-ray camera's were built (and are maintained) in the UK (the EPIC-MOS camera's pictured above-left);
• The optical/UV telescope was built in the UK;
• One X-ray camera (the EPIC-PN) was built in Germany;
• Two spectrometers (the RGS) were built in the Netherlands and the USA;
• All three X-ray mirror modules were built in Italy;
• Data analysis software and data storage by the UK & USA;
• The spacecraft was assembled in the Netherlands;
• The radiation monitors were built in France;
• Continuous XMM-Newton support is based in Spain, with support from the UK, Germany, France, Italy, Netherlands, and the USA;

XMM-Newton has made some amazing discoveries about the high-energy Universe in that decade. Lots of images from those XMM-Newton discoveries can be found online at the XMM-Newton image gallery, and a slideshow is available on the BBC News online website, narrated by myself (Dr Darren Baskill) and my colleague Dr Kathy Romer here at the University of Sussex's Department of Physics & Astronomy.

The EPIC-MOS cameras were built in the UK by a team led by Martin Turner, who had helped plan and build XMM-Newton over more than 25 years, until his death 6 months ago. The last time I spoke to him, we were discussing how to celebrate XMM-Newton's 10th birthday. All our celebrations of the great success of XMM-Newton are done in the memory of Martin.

December's Night Sky

This is the month to take advantage of, and enjoy, the long nights!

The earliest sunset here in southern England occurs at 15:54 on the 12th of December, and the shortest day is on the 21^st this year. The Earth is tilted, and the shortest day occurs when that side of the Earth is tilted directly away from the Sun - and so the solstice actually occurs at a specific moment in time, at 17:46 on the 21^st December, 2009.

The increasingly inaccurately named summer-triangle is still visible, low in the west, but only until 7.30pm - ideal for after-school observing events! And the Andromeda galaxy is still well placed in the evening sky (see last months posting for full details about both of those).

Jupiter is still a wonderful sight until about 8pm throughout the month - just look for the brightest object you can find, low in the west, and that will be Jupiter! Look through binoculars or a small telescope to see four of the 60 moons that orbit this gas giant.

The 21^st of December is a great day for a photo' opportunity. That late afternoon and early evening, the planet Jupiter is visible just below the Moon. And just to the top-right of Jupiter, is the planet Neptune - although you will need a telescope to see Neptune, as it is 10,000 times fainter than Jupiter!

Rising at 8pm in the east is the constellation of Orion - a very familiar sight in the winter skies, thanks to the three stars that form a straight line, and which are known as Orion's belt (as in the photo to the left). Just below those three stars in a line, are another group of three stars in a line... only, the middle star is not a star at all, but a huge gas cloud where stars are in the process of forming. You can see it with your own eyes, but look through a telescope and you can see much more detail, and take a long exposure photo', and you can see even more detail! The movie below shows the difference between looking through a telescope yourself, and taking a 15 minute long exposure photograph.

You can get some very easy-to-use and clear star maps from either Skymaps.com, or by using the excellent (and free) Stellarium Planetarium software.

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...!