I went back for another shot at Comet C/2021 A1 (Leonard) in the early morning hours of November 29th. At around 04:30 a.m. the comet finally climbed above the trees and roofline and I was able to get to work.
The imaging conditions weren’t ideal. There was a bright waning crescent Moon nearby and I was looking to the southeast into the eastern side of the Oklahoma City light dome. Nevertheless, I did capture some images. Here’s what I caught.
This single image is actually a stack of 36 separate images. Each image in the stack was aligned on the comet, essentially holding it stationary against the east-to-west movement of the night sky. The stars, on the other hand, continued to move, leaving trailed images. The star trails indicate the direction of the comet’s movement. The comet’s tail points away from the Sun.[1]This time-lapse animation covers nearly an hour’s worth of movement. At the time these images were captured, Comet C/2021 A1 (Leonard) was moving at approximately 3.5 arcminutes per hour across a rather barren patch of sky in the constellation Coma Berenices. The field of view of this image is approximately 18×14 arcminutes. North is up. East is left.[2]At the time these images were captured, observers were reporting A1 Leonard’s brightness as being between magnitudes 7-8. But, the comet is expected to brighten considerably during this next week. It should be a good binocular object at magnitude 4-5 December 6-10. It will rise around 03:00 a.m., and between 05:00-06:00 a.m. will still be low in the east, but high enough to be seen. After December 10th, Comet A1 Leonard drops lower and lower in the eastern sky and will be lost in the sunrise.
Notes:
1. Comet C/2021 A1 (Leonard), November 29, 2021, 10:54:49-11:59:28 UT
Stack of 36 images. 6 frames per image at 20 seconds per image (120 seconds total integration).
Telescope: Meade SN-8 (203mm f/4). Camera: ZWO ASI224MC.
2. Comet C/2021 A1 (Leonard), November 29, 2021, 10:54:49-11:59:28 UT.
31-Image time lapse animation sequence. 6 frames per image at 20 seconds per image (120 seconds total integration). Telescope: Meade SN-8 (203mm f/4). Camera: ZWO ASI224MC.
The morning hours between midnight and dawn were productive on November 26th. I captured three comets. The first of the bunch is Comet 4P/Faye.
The images below were captured over a one-hour period. They give some idea of how quickly this comet moves across the sky. As these things go, 4P is a relatively slow mover. It’s movement on this night was 0.28 arcminutes per hour. By comparison, Comet 2021 A1 Leonard, also visible, was moving at a much faster clip of 2.5 arcminutes per hour.
Wide View Stacked on Comet
Comet 4P/Faye on the morning of November 26, 2021. This image is a stack of ten images taken over a one-hour period. The images were stacked on the comet so the background star stars leave streaks or trails. The star trails give an indication of the comet’s movement over the one-hour period. The field of view of this image is 19×15 arcminutes (slightly cropped from the original). North is up. East is left.[1]Wide View Animation
In this wide view animation, 4P/Faye moves slowly against the stationary background stars. Here, ten images were stacked on the stars and are played back one at a time making the comet appear to move against a stationary background of stars. This one-hour time lapse is slightly cropped from the original. The field of view is 19×15 arcminutes. North is up. East is left.[2]Zoomed-In Animation
In this zoomed-in animation, 4P/Faye appears to move a little more quickly against the stationary background stars. This one-hour time lapse is a cropped area from the original from the original wide view. The field of view is 7×5 arcminutes. A tiny tail is barely visible pointing off to the northwest. North is up. East is left.[3]Comet 4P/Faye passed perihelion on September 8th and is moving towards its closest approach to Earth on December 5th. 4P/Faye’s close approach distance will be 0.94 AU (87,000,000 miles).
Magnitude updates aren’t being reported frequently, or regularly, on this comet. The most recent I could find at the COBS database put the comet’s magnitude at 11.6 on November 13th. My unofficial photometry shows a magnitude of 11.5 on these November 26th images. If my magnitude estimate is correct, 4P’s brightness has remained relatively stable over the last two weeks.
Notes:
1. November 26, 2021 06:28:18-07:25:32 UT
10 stacked images. Each image consists of 5 subs at 60 seconds.
FOV: 19.5×15.2 arcminutes.
Telescope: Meade SN-8. Camera: ZWO ASI224MC.
2. November 26, 2021 06:28:18-07:25:32 UT
One hour time lapse. Cropped slightly from original.
10 image animation. Each image consists of 5 subs at 60 seconds.
FOV: 19.5×15.2 arcminutes.
Telescope: Meade SN-8 Camera: ZWO ASI224MC
3.November 26, 2021 06:28:18-07:25:32 UT
One hour time lapse. Cropped and resized from original.
10 image animation. Each image consists of 5 subs at 60 seconds.
FOV: 7.13×4.97 arcminutes.
Telescope: Meade SN-8. Camera: ZWO ASI224MC.
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.
