Astronomy Blog

Where is it looking? - part 2

When people visit working astronomical observatories one of the questions they often ask is "where is it looking?". There is something quite exciting about knowing that the telescope you are stood next to is staring at a planetary nebula or perhaps measuring the lensed light of some of the most distant objects we can see in the universe. You are seeing awesome scientific research in action.

One of my aims is to make it easy to answer this question. As of a year ago, there were already a couple of observatories that provided real-time information on their websites. That is a good start but to do cool things with the data - such as piping it into Google Sky or MS World Wide Telescope - required people with some coding know-how to make custom programs to parse them. As long-term readers of this blog will know, I've been gradually edging towards making this a bit easier and getting the question answered for as many telescopes as possible.

My first step was to get the Jodrell Bank and MERLIN telescopes onto Twitter. Twitter isn't ideal as it only allows 140 characters, but as a by-product it created a fairly consistent RSS feed. My next step was to define a basic XML format (see posts 1, 2, 3 and 4) that would display just enough basic telescope information to be usable and still easy enough for most people to create. If you have the need, you can now grab the telescope pointing information in a consistent set of XML files. There is even a Google Sky version - just post the kml feed address into the search box if you use the web-based Google Sky. On an aside I'll admit that until today there had been an epoch error with the Google Sky feed; sometimes the telescopes were pointing at the B1950 coordinates rather than J2000. That is all sorted now thanks to some great tools I downloaded for some other ideas I'm working on (more on those some other time).

There are still some things that need doing. First of all, the output still isn't great. One problem I have is knowing what object is actually being observed. This is known to the array controller but is not accessible to the interwebs due to various historical and technical restraints. To get around this I use a look-up table of likely radio objects that includes pulsars, calibration sources, galaxies, and some recent supernovae. Effectively, I semi-intelligently guess the likely object. I know there are excellent tools such as NED and Simbad that can do look-ups by position but just taking the object nearest to the reported (and slightly degraded) position isn't always the best thing to do. Perhaps future control systems for e-MERLIN will provide easier access to the information. That is a potted history of where I've got to.

I should note that other people such as Alasdair Allan have already put Virtual Observatory Event notifications on the web in a variety of formats including Google Sky tupperware. I see that as complementary to what I'm doing.

My plan now is to start getting other telescopes to do similar things in time for the International Year of Astronomy 2009. If you have access to telescope pointing information - professional or amateur - I would encourage you to let people know what your scope is looking at by providing the information in one easy to consume format or another. Let's fill Stellarium, Google Sky, World Wide Telescope and a multitude of other web-enabled applications with real-time observations.