la palma – Matthew J Green

August 1, 2017December 17, 2017

I Should Have Brought A Better Camera

I don’t have much to say for this one, just a random collection of poor-quality phone pictures. Coming to the end of an observing trip (my first solo!). Six nights on La Palma — 2 on the INT and 3 on the WHT, with a night off in the middle. Pictures all from around the observatory.

The William Herschel Telescope, where I’ve been observing for the past 3 nights.

The National Galileo Telescope, opening ready for sunset. Telescopes always open before sunset to ventilate the dome, otherwise the temperature difference between inside and outside causes turbulence which reduces the quality of image they can take.

Two solar telescopes: the Dutch Open Telescope and the Swedish Solar Telescope. Very different designs to the night-time telescopes. (Unfortunately it seems like the DOT isn’t active due to a lack of funding.)

Since I had some free time this afternoon before sunset, I drove up to the viewpoint at the top of the observatory, from which you can see into the caldera of the volcano, as well as pretty good views in every other direction.

Looking down the length of the island. In the foreground is part of the caldera (the crater) of the volcano, behind is the mountain ridge and the sea.

In the other direction, telescopes in a line: NOT, WHT, DOT, SST, INT and JKT.

The other day I had a night off without a car. I decided to walk up to the GTC after dinner, which meant I happened to be there to watch it open at sunset. The GTC is the Grand Telescope of the Canaries, the biggest telescope in the world as measured by the diameter of its mirror (10.4m). It was quite dusty that day (the Canary Islands are downwind of the Sahara so often experience these dust clouds). Unfortunately my phone didn’t handle the contrast very well so the pictures weren’t great. It was cool to watch though.

July 30, 2017July 30, 2017

Observing at the INT

The Isaac Newton Telescope is my new favourite telescope. Most telescopes the observer isn’t allowed to touch the controls for the telescope itself; we just control the instrument. At the INT you observe alone, meaning you control both. Driving the telescope is easier than I expected. For the most part it’s done from the command line — just type ‘gocat’ and the name of your star and the telescope moves itself to point to it. There are times though that you have to switch the telescope over to ‘engineering mode’, at which point you drive it with the big bank of switches on the right. There’s a window through which you can see into the telescope dome, and a microphone so you can hear the various parts moving. You also use the same buttons to open the dome up at the start of the night.

At the end of the night you have to bring the telescope into ‘access park’, ie move it so that the end of the telescope is reachable from the balcony. This is the most intimidating part of the experience, as you have to override some of the safety checks to bring it so low, meaning that a couple of alarms will start going off — you then watch the telescope moving towards the balcony pretty fast, while you manually silence the alarms. Once it’s parked you have to go up and refill the camera’s liquid nitrogen supply, to keep it cooled to -160 degrees. It only takes around 5 minutes, but when you’ve been working all night and want to go to bed that feels like a long time.

Other than that the work is fairly easy; keeping an eye on the camera while it takes data. The control room is pretty cosy, with a coffee machine to keep you awake and a guitar to help you kill the time. You can wander off and explore the building if you want to, but do so at your own risk. The INT used to be the headquarters for the ING observatory, and much of the building is disused offices, meeting rooms, even a library. It’s a big building to be alone in all night, and you’d be surprised how much noise an empty building makes. Especially when you start to hear doors opening and closing…

July 27, 2017August 1, 2017

The “Warwick Empire”

NITES and the W1m. The grey sky is the ‘Calima’ – dust blown in from the Sahara.

I’m currently at La Palma, an observatory in the Canary Islands, to take data for someone in my department. Despite being comparatively close, I haven’t been here very often. It’s only the second time I’ve been here, and the first for over a year. While it’s not my favourite observatory, I enjoy seeing so many famous telescopes in one place — all the telescopes I’ve heard the most talk about are here, within a 5 minute drive of each other.

Among these is the “Warwick Observatory” — a cluster of telescopes that my own University of Warwick is heavily involved in, in some cases leading. Among them is the Warwick 1m (unfortunately they decided not to go with the Warwick One-Metre-Big Automated Telescope, or WOMBAT). Beside it is NITES the 40cm telescope. In the other is WASP-North, which along with WASP-South has found well over 100 exoplanets. Tucked away behind WASP is MASCARA, an ingenious Leiden-led project which effectively consists of 5 digital cameras pointed at the sky. I wrote an article about MASCARA recently, here.

It was particularly cool to get to see GOTO, the brand-new telescope array from the Warwick/Sheffield/Monash collaboration. The PI of the project is Danny Steeghs, one of my supervisors. The telescope was only assembled in its dome within the past month or two, so not too many people have seen it yet, and the official inauguration ceremony was just a few weeks ago. It’s still in its early stages — eventually there will be 8 telescopes mounted on the frame rather than 4, and another dome with the same setup next door.

GOTO is designed to follow-up on gravitational wave events by looking for visible light coming from the same source. Whenever a gravitational wave event is detected — so far four have been — GOTO will pivot to that patch of sky and scan for new light sources. Its parallel telescopes give it a wider field of view, necessary because it needs to cover a large area of sky as quickly as possible.