After 3 days I have now finished all the metalwork, drilling and tapping, and reconfiguring the top plate of the mini-WASP array.
The top plate will now accommodate 2 x Canon 200mm prime lenses, each with a Starlight Xpress M26C Trius OSC CCD + an Altair finder scope with a Philips web cam attached.
I’ve said it before but this time I think that’s really it as I simply cannot bolt anything else onto the frame.
With this final incarnation I think a name change is also in order – so what was the mini-WASP array is now officially titled the mega-WASP array.
The array can be run as two separate imaging systems (the limitation of the dome aperture means I cannot run all cameras at the same time, which is a great shame).
System 1: The very wide field imager. This is the 2 Canon lenses with M26C Trius cameras. Both lenses/cameras image the SAME object, so I am getting data down at a rate that is 2x the actual imaging time. The FOV of the system is 4.46 x 6.64 degrees with a sampling of 6 arcseconds per pixel. The M26C Trius cameras are 10-megapixel resolution. The Canon lenses are run with their apertures wide open and I use a 52mm UV/IR cut filter on the front which doubles as both a filter and an aperture giving f#3.8 operation and good quality stars across the whole of the M26C chip. The bonus of aperturing the lens in this way is that you don’t get the 8-spiked star spikes which I personally find pretty unattractive. You get no spikes at all with the Canon lenses used in this way, just as with a refractor.
System 2: The Sky 90 array. This system comprises 3 x Sky 90 imaging refractors each with an M26C (non-Trius) OSC CCD. Two of the three refractors have a filter-wheel attached with IDAS, H-alpha, H-Beta, OIII and SII filters. Again, each imager images the same object which gives me a data rate of 3x the actual imaging time. The FOV of a Sky 90/M26C is 3.33 x 2.22 degrees at a sampling of 3 arcseconds per pixel. All three Sky 90s have the Takahashi reducer/corrector fitted so the f# of a Sky 90 is f4.5. The fourth slot in the main frame houses the Megrez 80mm William Optics guide scope with a Starlight Xpress guide camera (driven from one of the M26C cameras). This guider also acts as a guider for the 2 Canon lenses on the top plate.
O.K. so we are never going to get enough clear Moonless skies to justify all this lot – but at least for those short opportunities, when they finally do come along, I can make the best of the time given to me by the weather Gods.
Pics will follow when everything has been set up. tuned in, and running 🙂 🙂
