Remote Observations of Remote Objects
On a balmy Friday evening in September, nearly 50 people squeezed into The Cabin at the Reserve to receive an illustrated talk from Tim Long on the new “Tigra Automatic Observatory: How we built it – What it does – How it works”. The majority of those present hadn’t been to a Stargazers’ event before and attended subsequent to an earlier visit to the Reserve on our successful Heritage Open Day. Here is a summary of Tim’s talk …
In the beginning … some of the components of the observatory structure, mainly the dome, resided at Tim’s home in South Wales, followed by a period in storage after his move to Canterbury. Tim decided to put these resources to good use and in the autumn of 2014 set about building our second observatory at the Reserve, assisted by Stargazers’ staff and volunteers.
While the structure itself was fairly straightforward to construct, what was installed inside did take some sorting out. For example, Tim had to work with a company based in Deal for 14 months to develop a bespoke drive system: apparently, such items are not available ‘off the shelf’. Commissioning the new observatory also took a little while due to ‘niggling problems’ such as the shutters not shutting (essential to keep the rain out!), and “fishy stars” (caused by a bolt pushing on the telescope mirror). But, with some perseverance, late nights, and hours of pensive thought, these problems were identified and resolved, and the new Tigra Automatic Observatory became fully operational. However, the problems didn’t stop there …
Shortly after the first trial photos using the new observatory and equipment inside were taken, disaster struck! The special astronomical camera failed completely, beyond repair; and it wasn’t just a standard digital camera either – it cost $8,000 when new. (Ouch!). However, a crowd-funding exercise managed to secure the fantastic sum of £12,000 to buy a new camera. Then the observatory kept running out of power, due to running off batteries recharged from solar panels. This was overcome when mains electricity arrived at the Reserve in April 2017. An internet connection was also required at the observatory, which was solved by installing radio links to the hub in the Reserve’s main building. Problems, problems …
Please note that at this point in his talk Tim then expanded on the details of the instrumentation within the observatory, covering lots of ‘tekkie stuff’. I’m sure he will be pleased to inform you about this sometime, but I’ve excluded it for brevity and clarity in this write-up – not because I didn’t understand it all 😊.
Anyway, if you haven’t gathered by now, the main purpose of the Tigra Automatic Observatory (TAO) is to facilitate astronomical observations, both automatically and remotely. This means that the whole operation can be controlled from a remote computer, via the internet web-links; and this can either be done live (as demonstrated by Tim on the night) or programmed to take certain observations in advance. Wow!
One of the most interesting aspects of the talk for me was learning how difficult astronomical photography can be. To get a good ‘shot’ of a star, or even worse, a ‘deep space object’ such as another galaxy, requires long exposure times, possibly up to five minutes. During this time the Earth continues to rotate, so in photos of the night sky stars will appear as curved streaks (all rotating around Polaris, the Pole Star) if a long-exposure picture is taken with a normal digital camera or even through a cheap telescope.
But better ‘scopes can overcome this by tracking the object star, or (as the case with the TAO) tracking another star using “off-axis guiding”. This ensures that the viewed object stays absolutely in the same position in the photographic frame, enabling extremely fine focussing and pin-sharp images. Complicated huh?
Another interesting aspect of the TAO is “Skynet” (nothing to do with The Terminator!). This is a weather monitoring system operating at the observatory that decides when it is safe to open the shutters, coupled with a period when there are clear skies to allow observing. Clever huh?
There is so much more about the Tigra Automatic Observatory than I have space to expand upon here. So, if you do want to know more, why not come along to a Stargazers’ event and speak to Tim directly, I’m sure he will be delighted to share his knowledge and the workings of the TAO with you.
Meanwhile, I’m looking to the further developments of this modern installation, and hopefully the time when I’ll be able to view what the TAO is looking at via a web-link (password protected of course) from the comfort of my own home. Watch this space (pun intended)!
Andrew Ogden, 07/11/2018