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Two Comets in One Night

2021 November 20

Sunday morning, November 14th, I caught two comets between midnight and dawn. The conditions weren’t ideal with occasional periods of gusty winds, the Moon approaching full, and waves of thin moon-illuminated clouds moving across the sky.  Nevertheless, I took a chance and captured images of comets  67/P Churyumov-Gerasimenko and C/2021 A1 (Leonard).

Both comets were in the eastern sky while the bright Moon was to the west.  Over at the Comet OBServation website (COBS), observers were reporting these comets between magnitude 8-9.

Comet 67/P Churyumov-Gerasimenko

Comet 67/P Churyumov-Gerasimenko November 14, 2021, 07:28:52-07:50:46 UT. FOV approximately 20×15 arcminutes. North Up. East left.[1]

Comet 67/P Churyumov-Gerasimenko November 14, 2021, 07:24:51-07:59:41UT. FOV approximately 20×15 arcminutes. North up. East left.[2]

Comet 67/P Churyumov-Gerasimenko November 14, 2021, 08:50:55-09:50:14 UT. FOV approximately 20×15 arcminutes. North up. East left.[3]

Comet C/2021 A1 Leonard

During the hour that I was imaging C/2021 A1 Leonard, the waves of moonlit clouds passing through the field of view increased in frequency. As a result, the captured images wouldn’t produce a good animation. I did, however, capture enough useable images for a single stacked image of the comet. 

 

Comet C/2021 A1 (Leonard), November 14, 2021, 10:48:05-11:40:01 UT. FOV approximately 20×15 arcminutes. North up. East left. [4]

 

Meade SN-8, 8-inch Schmidt-Newtonian (203mm f/4), with ZWO ASI224MC camera mounted in the eyepiece tube. The telescope and camera sit atop a Celestron CGEM mount.

Equipment

The telescope used for capturing these images was a Meade SN-8, an 8-inch Schmidt-Newtonian (203mm f/4). I pulled this scope out of the attic where it had been in retirement for the last 15 years. The camera was a ZWO ASI224MC. The 224MC is primarily a planetary imaging camera, but for deep sky objects in the magnitude range of these comets it seems to work pretty good.

 

 

 

 

 

Notes:

1. Stack of 6 Images. Each image is a stack of 17 subimages at 15 seconds each. The subimages captured and live-stacked in SharpCap. The resulting six images were stacked in Deep Sky Stacker. Color adjustment, crop, resize in GIMP. Telescope: Meade SNT-8 (203mm f/4). Camera: ZWO ASI 224 MC.

2. Animation stack of 9 Images. Each image is a stack of 16 subimages of 15 seconds each (total exposure for each image 240 seconds). The subimages were captured and live-stacked in SharpCap. Animation, color adjustment, crop, in GIMP. Telescope: Meade SNT-8 (203mm f/4)
Camera: ZWO ASI 224 MC.

3. Animation stack of 15 images. Each image is a stack  of 17 subimages of 15 seconds each (total exposure for each image 255 seconds).  The subimages were captured and live-stacked in SharpCap. Animation, color adjustment, crop in GIMP. Telescope: Meade SN-8 (203mm f/4) Camera: ZWO ASI224MC.

4. Stack of 12 Images. Each image a stack of 17 subimages at 15 seconds each. Subimages captured and live-stacked in SharpCap. The resulting 12 images were stacked in Deep Sky Stacker. Color adjustment, crop, resize in GIMP. Telescope: Meade SNT-8 (203mm f/4). Camera: ZWO ASI 224 MC.

 

 

 

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