Comet 12P/Pons-Brooks remains in the western sky–visible as twilight fades. But don’t wait too long in the evening or it gets too low in the western sky and becomes difficult to see. Also, it requires long exposure photographs or binoculars/telescope to see. There are projections that it may brighten to become just barely visible to the unaided eye in a few weeks.
I’ve had several opportunities recently to photography the comet including its positioning in the sky near the Andromeda Galaxy (M31). A normal to short telephoto lens (i.e, ~50 to 85mm) was a good choice for capturing both objects while a longer telephoto (i.e., 180mm or even 500mm) worked best for isolating the comet.
Of course, the comet is not the only object in the sky. Satellites are constantly moving across the sky. Fortunately, software can remove the tracks by stacking multiple photographs and taking the Median or the Mean value at each pixel. On the other hand, it can be useful to take the Max value at each pixel to illustrate the number of satellites crossing even a small portion of the sky in a short period of time.
Last week I was able to get some good images of Comet 144P/Kushida which was located in the constellation Taurus and near the star Aldebaran. Being this close to a bright star makes it fairly easy to find.
I first shot using an 80-200mm zoom lens. The short end (80mm) gave me a wide field of view to find the comet and then I zoomed to the long end (200mm). After about a half-hour of shooting I decided to switch to the 200-500mm zoom lens. Starting at 200mm to center the comet, I then zoomed to 500mm. The image above is the result of stacking 22 images (11 minutes exposure time) then post processing with rnc-color-stretch and finally, Lightroom and Photoshop. Above is a screen shot from the sky application Stellarium showing the field of view at 500mm.
Bonus: image of the waxing gibbous Moon a week later. The image was converted from RGB to L*a*b color space and then the two color channels were adjusted to bring out the subtle colors of the Moon.
This is the first of what will be many posts on this comet. Comet 12P/Pons-Brooks will be in the western sky in the evening for the next few months and could brighten enough to be visible to the unaided eye. Right now, however, it is quite dim at a magnitude of +9.0 and is located near the star Vega in the constellation Lyra.
Comet 12P/Pons-Brooks is a cryovolcanic comet. When exposed to the sun’s warmth the pressure within this cryomagma builds up until it triggers the release of gases, expelling icy fragments (and the gases) through cracks in the comet’s outer layer and into space. 12P has already had multiple bursts which have resulted in rapid brightening.
I ventured to Sunset Crater Volcano National Monument, an International Dark Sky Park, to shoot images of the comet. As noted above, it very close to the bright star Vega which made it very easy to find. My primary goal was to use my Nikon 180mm f/2.8 AIS lens, a legacy manual focus lens known for value in astrophotography and so that I could capture the full constellation. My secondary plan was to use the Nikon 200-500mm lens at its maximum zoom showing just Vega and 12P.
Owing to being a bit out of practice (it happens), both my focussing and star tracking were suboptimal. Something to work on for my next shoot.
This comet was discovered by Japanese amateur astronomer Hideo Nishimura. It was briefly visible in the morning twilight but became increasingly difficult as it got closer to the sun and was lost in the glare. It will very briefly be the evening sky this week but, again, the glare of the Sun may make it difficult to see.
Here are a few images taken in the pre-dawn hours on 08 September. In the foreground is Wukoki Pueblo in Wupatki National Monument.
Nikon D750, 85mm, f/2.8, ISO 3200, 10×3 seconds and stacked using Starry Landscape Stacker to reduce noise.
Comet C/2022 E3 (ZTF) continues to be a interesting object in the night sky for photography, telescopes, and binoculars. Unfortunately, it never got bright enough to be an easy object for the unaided eye. One could sometimes see it when viewing it from very dark locations without the Moon present–but usually only with averted vision. At its brightest it was reported to have reached magnitude +5. The comet should fade rather rapidly in February and may be as faint as magnitude +8 by the end of the month.
The comet made its closest approach to the sun on 12 January 2023 (1.11 AU; 166 million km) and its closest approach to Earth on 01 February 2023 (0.28 AU; 42 million km). See the included Solar System map that shows the location of the comet relative to Earth or visit TheSkyLive.com for an interactive version.
Here are a few of the better images I have been able to capture of the comet over the past few weeks. These have used a variety of lenses but always the same camera, tripod, and star tracker.
These photos were taken on 22 January 2023 using a manual focus Nikon NIKKOR 80-200mm f/4 AI-S zoom lens. This lens has the advantage of having a hard stop at ∞ making it very easy to focus. Image stacking was done using Deep Sky Stacker.
Both of these images of the comet show the tail (pointing up) and the antitail (pointing down). From Wikipedia:
An antitail is an apparent spike projecting from a comet’s coma which seems to go towards the Sun, and thus geometrically opposite to the other tails: the ion tail and the dust tail. However, this phenomenon is an optical illusion that is seen from the Earth…
And here is a time-lapse movie of the motion of the comet during the period 0359 through 0435 MST.
Time-lapse video of Comet C/2022 E3 (ZTF) from 0358–0454 MST 22 January 2023.
A few days later I was able to capture both the dust tail and the ion tail. Stacking was done using Deep Sky Stacker. This was shot with the Nikon NIKKOR ED 180mm f/2.8 AI-S manual focus lens.