Category Archives: Comets

Comet 41P on Feb 23, 2017

Comet 41P on Feb 23, 2017, 03:34 UT. 3×360 and 24×120 sec @ ISO 1600, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star Freeze version.
Comet 41P on Feb 23, 2017, 03:34 UT. 3×360 and 24×120 sec @ ISO 1600, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star Streaks version (3×360 subs as a base, Comet only from 24×120 subs.)

A different comet is out and about now.  Periodic comet 41P is coming back around and is conveniently placed in Leo and so is up most of the night.    I shot it from a darker sky location and it turned out OK, I guess.   It was a little dimmer than I expected.

I was pressed for time this session, so I went with 2 minute ISO 1600 exposures to match the darks I had already taken for another object.   It really needed a little longer exposure and more ISO.    Next time, I’ll hit it with 3 minutes and ISO 3200, which I hope will be in two days after this was posted.

Comet 41P, Feb 23, 2017, 03:34 UT. Star Streaks version with just the 24×120 sec ISO 1600 sub-images.

They say this comet will get better during March, so I’ll probably be shooting it again soon.

Comet Encke, Feb 23, 2017, 01:22 UT

Comet Encke, Feb 23, 2017, 01:22 UT. 12×120 sec @ ISO 1600, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD.

This is probably my last Comet Encke shot for this go-around.  It is so close to the horizon at the end of astronomical twilight that it is hard to get any good data.  Only if the horizon is exceptionally clear from this point forward will I attempt to shoot it again.

It still shows a nice tail, despite being in the muck at the horizon.   The negative insert shows the tail the best, but it is also somewhat visible even in the positive image.

I had guiding issues for this shot, so I was not expecting much of an image from the data.  But, it still came out OK despite that.

Comet Encke on Feb 19, 2017, 01:02 UT

Comet Encke, Feb 19, 2017, 01:02 UT (Feb 18, 2017, 7:02 PM CST.)

I did it.  I drove out of the city to a new spot I found on a Light Pollution Map.   It was only 30 to 40 minutes away and very dark by today’s standards.  It is a dead-end Parish road with no houses for a few miles, which means I didn’t have to trespass on someone’s property.  I just stopped at the end of the asphalt and setup shop.  🙂

I was able to shoot with ISO 3200 even with Comet Encke close to the horizon.   It was dark enough to notice a little zodiacal light there, too.   With these kinds of conditions, I was able to pick up Encke’s tail.

The data was shot in three sets.  Two sets of 15×30 sec @ ISO 400 and 7×30 sec @ ISO 3200 while it was still twilight and finally a set of 37×60 sec @ ISO 3200 started just before twilight officially began.  About 48 minutes total integration.

The main image has been cropped, but the enhanced negative insert is more of the full field.  You can see that the tail actually goes out of the field of view.  Amazing!

Alternate version without the labels or negative insert. Dynamic stretch instead of Color stretch.

 

Two enhancements that show tail length.

Unfortunately, Comet Encke is all I got this evening.  While I was doing a better polar alignment and setting up to shoot the Horse Head, a huge fog bank rolled in quicker than I even noticed and it was thick.   Oh, well…   I took that as my cue and shot my calibration frames and left.

I also did a star freeze rendition and it came out ok.  It just doesn’t show the tail as well as any of the above images:

Comet Encke, Feb 19, 2017 – Star Freeze Version.

Comet Encke and Ome Pisces

Comet Encke and Ome Pisces on Feb 16, 2017 00:54 UT. 16×30 sec @ ISO 200, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD.

Not much to look at here.  Comet Encke was next to one of the brighter stars in Pisces and deep in the muck and haze of LP and poor transparency skies.   I was lucky to get even this much.

Here’s just the comet centered in a close crop that excludes the bright star:

Comet Encke. 16×30 sec @ ISO 200 plus 4×30 sec @ ISO 100, Televue TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD.

Comet 45p on Feb 10, 2017

Comet 45P, Feb 10, 2017, 09:54 UT. 52×60 sec @ ISO 800, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. StarFreeze version.

Taken in bright moonlight and bad LP in the hours before dawn on Feb 10, 2017.   45P is so dim that it barely showed up in the sub-images.  I almost thought I was not in the right place.    Luckily, I kept the scope pointed at that spot and kept shooting images until daylight.

Comet 45P, Feb 10, 2017, 09:54 UT. 52×60 sec @ ISO 800, TV-85 at F/5.6, Canon T3, Atlas EQ-G w/EQMOD. Star-streaks version.