This will go down as one of the greatest and most important photographic discoveries of the century. It doesn’t look like much, but the face third from the left is none other than that of Vincent Van Gogh attending an outdoor dinner party on a cold December in 1887. It’s significance? It’s the only photographic image ever to have been taken of the artist.
Just five years ago NASA launched the Keplar spacecraft into orbit at a cost of $600 million dollars on a quest to search our Milky Way galaxy for signs of exoplanets, or planets orbiting stars other than our own. In November, amateur astronomer David Schneider managed to detect one in his back yard using less than $500 of DSLR equipment. In fact, he didn’t even use a telescope.
Schneider, also a senior editor at IEEE Spectrum like the rest of us thought that only hardcore astronomers using expensive imaging and radio equipment had the tools to detect exoplanets. That was until he came across the KELT-North project by Ohio State university. whereby a group of students who had repurposed a CCD sensor to a high end camera lens and were able to detect several previously known exoplanets. With the amateur astrophotographer in mind, Schneider challenged himself with visualising an exoplanet with standard camera equipment.
Apart from requiring a standard sky tracker mount – An electronic geared system that guides your camera along the equatorial, thereby following the night sky – which would cost anywhere between $100-$1000 the only tools needed for the job were a DSLR camera, tripod and telephoto lens. What makes this even more remarkable is that Schneider used a $72 Nikon lens, with a Canon convertor ring to do the job – Heath Robinson or what?
The star chosen in question was HD189733, known to home a massive Jupiter sized planet that orbits the star once every three days. Perfect for this experiment. What Schneider would be looking out for is the transit period, where the planet passes in front of its home star thus causing a dip in brightness. This is known as transit photometry, the most commonly known way to discover exoplanets.
The dip in brightness is unfortunately too insignificant to visualise in a pair of photo frames, not to mention the many variables that would effect any attempt at detection this way, so Schneider downloaded some free software to automatically analyse the different frames taken which revealed, as expected a transit period of about 1 hour and 48 minutes. The data visualised into a photometry chart reveals, with no stretch of the imagination a dip in brightness. We are sure that if the experiment was repeated several times the curve would only get more apparent.
What I feel is most important about Schneider’s ‘discovery’ is that even though this particular exoplanet is a well known object, it proves that anybody with a camera and just enough knowledge can search for their very own exoplanets. I hope, no, I expect the first completely amateur exoplanet discovery to be made soon and I believe David Schneider will be able to take some credit in that.