Tag Archives: M1

Start M1 with Luminance

Last night was not only clear, it was excellent. Clear, moderate seeing, no moon, and temperature only about -3°C. It’s late enough in the year now that the Orion area is now above my high horizon. With the AT8 scope presently mounted, I started on M1. Mount was performing very well – tracking very well on its own, and autoguiding to around 1 arcsecond (which is less than seeing jitter, and so just a guess).

Here is the start of M1, the Crab Nebula. This is 2 hours of luminance as 24 5-minute subframes. It’s going to be clouds for many days now, so I’ll add colour later if and when the sky permits.

Clear night: More M27 time and some other targets

November 9, 2010. The moon has set and, with DST over but no snow cover yet, it is surprisingly dark in my back yard. It’s clear and not too cold – about 5 degrees.

Gathered 2 more hours of data on M27, this time in 15-minute subs. I’ve bumped this up from 10-minute subs just to see the effect. I would expect slightly deeper results, and slightly better S/N, than with more shorter subs. On the other hand, the longer the exposures, the greater the chance that something like a passing plane will ruin them. So I’ll try 15 and see how that works, and maybe push even longer for the next run.

Watching the guiding graph, I note that RA guiding is still tending to oscillate back-and-forth across the zero axis, so I have tried turning the x-aggressiveness down a bit, to 60%, to see if it can further smooth out the curve. Watching the results for a couple of minutes, it does seem to have resulted in a flatter error curve. Continue reading →