Wednesday, 17 November 2010

California here we come

This is a little bit of the California nebula (NGC 1499) taken with the autoguided 20" scope. I combined 6 x 90 second exposures. It makes sense in theory to get as long exposures as possible, because it's not just a case of taking more shorter exposures. With the longer exposures, there is less noise, because a large part of the noise is from reading the sensor. The problem we have is rotation, which limits the exposure time until you see stars forming short trailed arcs at a distance from the guide star. Therefore, we can only do long exposures in the East or West. Had my camera been modified for astronomy, this picture would be full of bright red nebula.
As it is, it is pink, but still lovely.

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