Comet Lovejoy

Tonight I took a chance I could see Comet C/2014 Q2 Lovejoy from my 3rd floor patio. I rarely image from my patio because the sky is mostly blocked by trees and the overhang of the patio. Because the altitude of the comet would be about 60 deg I needed to get the C8 AVX setup early and the Meade DSI equilibrated before the comet was hidden by the patio overhang. I used the AVX Quick Align and syncing on Aldebaran since Lovejoy was in Taurus. I was able to cool down the DSI using the optional fan and collected some quick dark frames between 1s and 15s  around 1C. The comet is surprisingly bright and was able to image with a series of 5.7s exposures. I only accumulated about 10 frames. The result appears below. If I'm lucky I'll get to my local park site and get a better image later this month.

Celestron AVX + Meade DSI -- part 2

This blog is about the Meade DSI which I've had since 2011 using with both enjoyment and frustration. In recent years my frustration has been with stubborn CCD hot pixels that persist despite being subtracted by dark frames.

Based on a comment by another DSI user I have started only acquiring dark frames for the exposure time I will use for the next target deep sky object(DSO). This saves time and ensures fresh dark frames for each new image acquisition. DSI will complain if there is no 1s exposure dark frame for the current temperature. Thus I collect dark frames between 1s and 8s. 

All of my imaging to date has been unguided as I have not been willing to invest a second imager, scope, etc needed to automatically guide the mount. That said, the AVX mount tracks beautifully even without periodic error correction(PEC) training.

One of the really great features in the AVX is the "All Sky Polar Alignment". After doing a two star alignment and refining go-to accuracy with four calibration stars  you can refine the accuracy of the polar alignment by pointing to a star near the meridian and following the All Sky Polar Alignment procedure. The procedure saves a ton of time compared to the drift alignment method 

My most recent imaging has been in Maryland where clear nights have been few the last couple of weeks and seeing has sucked. In any case a few images will be shown in the next post(s).

Also, because of the small size of the Meade DSI CCD chip I use a fairly aggressive focal reduction strategy. I always keep an Atik 0.5X  focal reducer screwed into the DSI. This also serves to protect against dust. I also have a Celestron 0.67 field flattening focal reducer for more extended targets such as M42. As will be seen in part 3