Here at Hackaday, we pride ourselves on showcasing the latest hacks and the best of what’s happening in the world of hardware hacking today. But sometimes we stumble across a hack from the past that’s so compelling that we have to show it to you, so we can all marvel at what was possible in the Before Times.
This, a completely home-built automatic photometric telescope, was designed and built by the father-son team of [Jack Ells] And [Peter Ells]. From the elder [Ells]’ field notes, the telescope saw first light in 1988, which gives us an idea of the scale of the problems that had to be overcome to get this amazing machine up and running. The optics are simple, at least for telescopes — it’s a F-4.0 Newtonian reflector with an 8.5″ (221 mm) primary mirror on an equatorial mount. The telescope looks very robust indeed and is even supported on brick piers for stability. The telescope mount is controlled by a BBC Micro with custom BASIC software.
For the photometric parts, the [Ells] The boys installed a photomultiplier tube at the focus of the telescope. More specifically, they used a liquid light guide to connect the eyepiece to a rack of equipment, including the PM tube, the high-voltage power supply, and a series of signal conditioners and counter circuits. The idea was to look at a single star through a pinhole mask above the telescope objective and count the rate of photons received over time. If we did that, we would see periodic changes in the brightness of the star. Today, we would use similar data to search for exoplanet transits; while we don’t think that was a thing in 1988, it seems that this telescope could have done the job easily.
Unfortunately, [Jack Ells] died just two years after the telescope was finished. But he left it with his son, who eventually moved it to a location with better viewing conditions, where it collected data for another eight years. The quality of the work is astonishing, and as far as father-son projects go, this is a tough one to beat.