[OzEclipse (Joe Cali)]

Had a nice albeit short session last night. Clouds were predicted to arrive 60 mins after astronomical twilight. The weather prediction out here is very accurate. Cloud arrival is usually within ±30 mins of the hourly model.

I set up my 6" f7 during twilight. The mount, made mostly from aluminium, is quite robust and weather resistant but has spent a lot of time out in the weather uncovered for the past 2 years so I had stripped it down, replaced the lube and a few rusted steel socket cap machine screws.

The OTA had been inside the cool house all day and didn't need any cool down time. Seeing was pretty good and I was enjoying steady 200x views of Jupiter from the get-go during nautical twilight.

I went inside shut the blinds and turned on the household red lighting. Soon after astronomical twilight hit, I pointed the scope at C/144P Kushida located immediately adjacent to the Hyades.

Sky conditions for that first hour were outstanding. Transparency was excellent with the sky inky black between stars and probably somewhere between Bortle 1 and 2. Sky here varies from Bortle 1-4 depending critically upon particulates (pollen, smoke, dust) in the air. However the earlier excellent seeing rapidly deteriorated from 4/5 to 2/5.

The comet's coma was about 10' diameter, fairly round with a faint indistinct nucleus possibly around Mv 12.5-13.
I didn't try to estimate brightness. Clouds were coming in fast. I could see Jupiter already in a diffuse haze and I doubted I'd have time to complete the estimate. The most recent estimates that have been reported are around Mv 10.2.

I produced the attached digital sketch indoors immediately afterwards. Didn't want to use any light at all at the telescope with the comet so faint.

Looks like I'll have a few days of clouds then a run of clear so, I'll get the 18" out from Wednesday on and get a good look at it.


Joe