Comet Johnson, Feb 26, 2017

Comet Johnson, Feb 26, 2017, 08:35 UT. 18×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star Freeze version.
Comet Johnson, Feb 26, 2017, 08:35 UT. 18×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star Streaks version.

I was able to catch 4 comets on the night of Feb 25/26th, 2017.  Comet Johnson was the last one of the night and I got some good data on it this time.

I have processed the data like usual and included both a star freeze and star streaks version.    I cropped these close at 100% full size.

The full frame is below:

Comet Johnson, Feb 26, 2017, 08:35 UT. 18×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star Freeze full frame version.

 

Update Feb 27, 2017:
I actually made a mistake on processing these and the exposure time involved.   There are only two (2) sub-images that were shot for 3 minutes at ISO 3200 (the first two) and the remaining sixteen were all 5 minute subs at ISO 1600.   Doh!  😮

Update Feb 28, 2017:
I had processed them with the 180 sec, ISO 3200 darks and offsets and it still came out.   I wrongly stated to myself (and this blog) that I would not reprocess them with the right calibration data, since it looked good enough.  However, I’m glad I changed my mind:

Comet Johnson, Feb 26, 2017, 05:00 UT. 16×300 sec @ ISO 1600, TV-85 at F/5.6, Canon T3.

This was much cleaner in the reprocess.  I have two layers here.  One is the comet and one is the star background.  I didn’t have to slice and dice 10 different processing attempts and put together an image.  I only used the minimum needed.   Nothing from the first processing job was used.

Comet 45P on Feb 26, 2017

Comet 45P, Feb 26, 2017, 07:11 UT. 24×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD.

Because of weather, I missed out on imaging Comet 45P when it was near a famous galaxy pair recently.    I finally got to image it from a relatively dark sky location on Feb 26, 2017.   There were no “famous” galaxies in the vicinity this night, but there were sure lots of faint fuzzies in the image to make it interesting.

The star freeze version above came out OK.  Not too bad.  I also did a star-streaks version and I’ve included that below.

Comet 45P on Feb 26, 2017, 07:11 UT. Star-streaks version.

Keen observers will note that there is an asteroid in the tail of Comet 45P.   It can be seen in both versions.   I’m pretty sure that is 5081 Sanguin (1976 WC1).

Comet 41P, Feb 26, 2017, 05:00 UT

Comet 41P, Feb 26, 2017, 05:00 UT. 34×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star-Streaks close crop version.
Comet 41P, Feb 26, 2017, 05:00 UT. 34×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. StarFreeze version.
Comet 41P, Feb 26, 2017, 05:00 UT. 34×180 sec @ ISO 3200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star-Streaks version.

At about 11:00 PM CST on Saturday night, Feb 25th, I decided that I’d hit Comet 41P again.   This time with a longer session, more exposure and a higher ISO.    These images are the results of that endeavor.

The Pleiades, Feb 25, 2017

The Pleiades, Feb 25, 2017. 31×300 sec @ ISO 1600, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD.

It was a beautiful evening and I just had to shoot the Pleiades (M45) from my new dark sky site.  They just looked too good from there.

I wanted see how much I could pick up with the unmodified Canon T3.  It is definitely a camera that is sensitive to blues and cyan.  It does comets and galaxies well enough.  It is not as good as a modified camera on nebulae, unless its a reflection nebula like M45.

This is about 2.58 hours of integration – about the minimum needed to bring out that faint background nebulousity I’ve always tried to get.  It is difficult to decern the true background if there are any gradients, unfortunately.  There were a some here and I tried my best to minimize them.   Towards the end of the set, M45 moved into the muck and a little LP from a small neighborhood to my northwest.  Plus, the zodiacal light was contributing a gradient, too.   It was interesting to see that, though.  🙂

Below is the normal orientation for M45 with some noise reduction thrown in.  I didn’t do any to the first image.  That was pretty much how it came out after stacking.

The Pleiades, Feb 25, 2017. 31×300 sec @ ISO 1600, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Normal orientation.

 

And finally, the gaudy, maxed out version:

The Pleiades, Feb 25, 2017. 31×300 sec @ ISO 1600, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Gaudy maxed out version.

🙂