New record for the Society's 20" telescope

Being able to image the solar system's faint outer moons Triton, Hyperion, Phoebe has whet my appetite for obscure astronomical targets. I set to work looking for the solar system's outermost visible object, Eris (I still liked the name 'Xena' better). Eris is 96.7 astronomical units away. This is a crazy distance! Three times that of Pluto. It's therefore receiving 1/9th the light, and only 1/9th of THAT light will get back to Earth. This object really pushed the limits of my imaging system. This comprises of stepper motors, worm gears, an MS-DOS program, an Alt-az hand built Newtonian telescope, a field flattener and a Canon EOS 350D (at about 8ºC). The site is now fairly light-polluted but we have a dome. Eris was about 30 degrees up in the South when these images were taken (13 days apart). It has only moved a few arc minutes (mostly parallax shift) in this time because it is so far away and that is how it evaded detection before Jan 2005. It has a moon, Dysnomia, discovered Oct 2005. Using the moon to 'weigh' Eris, it is now known to be more massive and also larger than Pluto, thanks to Hubble's impressive measurement of its size. I really had to optimise the stacking and processing of each of these images. The second image (Eris on right) is noisier, despite more (43 (cf. 32)) 30 second images. These are cropped and put together into an animated gif.

See "littlebeck" blog on my links - for the necessary images that reassured me that my blobs were Eris.