Chile is large. So large in fact, that the distance from the UK to Chile is about the same as the boundary length of the country itself. Chile has large cities (Santiago has over 7 million people residing in the metropolitan area), large mountains (the Andes, around 4300 miles long, is the longest continental mountain range in the world, with the highest peak being over 13,000 ft above sea level), large deserts (the Atacama has an area of 54,000 square miles), large earthquakes (9.5 was the record in the ’60s)… and large telescopes. Very Large Telescopes.
The VLT The Very Large Telescopes (or the VLT, as us kids in the know call it) is situated at the Paranal observatory in the Atacama desert, approximately 800 miles away from Santiago. It takes a 2 hour plane journey over the Andes (stunning to look at) to the nearest city of Antofagasta (not so stunning to look at), followed by a 2 hour drive to get there. But my goodness, it’s worth it… The desert scenery looks like a watercolour painting with all of its variations in colour and shape (the banner at the top of this blog was a photo I took on my last trip to the observatory – the darker blue stripe is the ocean on the horizon!), the sky is the deepest shade of blue you could ever imagine, and best of all, it’s deathly quiet
The semi-subterranean astronomer’s residence – or “residencia” in Spanish – is well-known in the community for its hotel-esque qualities… Asides from the obvious bedrooms, offices and dining room (complete with a free ice cream machine! It tastes terrible, but you know! It’s free!), it boasts a cinema room with wall-to-wall DVDs, a music room complete with instruments, an arboretum, gym and a swimming pool. Honestly, I could quite happily move in! (as long as I could bring my own ice cream.).
Incidentally, if you ever watched the James Bond film “Quantum of Solace“, this is the building the spectacularly blew up towards the end… (click the link)
But of course, we’re not there to spend all day swimming (sadly)… We’re here to play with these:
So, there are four 8.2m VLT units that were called Unit (UT) 1, UT2, UT3 and – you guessed it – UT4. Apparently, this doesn’t really sound that inspiring to the non-technical types, so they hosted a competition a while back to rename the units. A Chilean teenager won in the end, and so now each has been given a name in the indigenous Mapuche tongue: Antu (Sun), Kueyen (Moon), Melipal (Southern Cross) and Yepun (Venus, in terms of it being a “morning star”).
Each unit contains a telescope possessing different instruments to do different kinds of science, but there is a central control room for all four in a separate building.
Unlike some other telescopes, having people come to visit to do their own observations isn’t something that’s done unless there’s decent justification (e.g. needs to operate in some special mode), and so they have a permanent staff of telescope operators (TOs) instead. I can almost here the audible sigh of relief from my work colleagues and collaborators around the world with the knowledge that I’m not allowed to put my grubby paws anywhere near the controls – I’ve developed a terrible reputation for breaking technical things just by being within a certain radius. I’m both amused and appalled at the number of times I’ve been told “try not to break anything”, asked “destroyed anything yet?”, or reminded “telescopes commit suicide when you go near them” (referring to one minor incident with the INT… It was like that when I got there!!). There’s a fantastic t-shirt for sale at http://www.thinkgeek.com with the slogan “I void warranties” written on the front of it. It’s top of my Christmas list.
… Anyway, there are also four 1.8m ‘auxillary’ telescopes (ATs) in front of the four main UTs:
As I mentioned before, each of the VLT telescopes possesses a mirror 8.2m in diameter, which is pretty much the limit for how large you can make such a mirror before it starts to deform under its own weight. Here’s a picture of the mirror – the dome is open here, so the reflection is the showing the outside world…
And here’s some more pictures showing complicated-looking techy bits of machinery:
As the sun goes down, the units get ready to observe – the dome and ventilation shafts are opened, and the telescope is put into position at zenith (pointing straight up)
The ATs are also positioned and opened up:
Whilst all this is going on, the observers go and stand together on the decking in front of the units to watch the stunning sunsets over the desert and distant ocean:
…And then the science happens 🙂 For this run, we were using the FORS spectrograph on UT1 to look at the central stars of some planetary nebulae (i.e. the stars the nebula forms from) to determine if it is in a binary system, and what classification of star it is. Some of this data will eventually end up in my thesis… (scary!). The next time I go observing, I’ll be joining both Dave and Henri (my other supervisor here) at the New Technology Telescope (NTT) at the La Silla observatory towards the end of the month for a 5-night run (although we’ll have to be there for about 10 days due to non-regular transport!). I’ve never been there before, so I’m very excited – let’s hope they do better ice cream. And don’t worry, I’ll try not to break anything…
Hasta la proxima,