Comet C/2023 A3 (Tsuchinshan-ATLAS)–Morning Observations

October 7, 2024 / Add comment

Comet C/2023 A3 (Tsuchinshan-ATLAS) has been in the headlines and the morning sky for a few weeks. Yeah, some of the headlines and news articles are over-the-top but most of them are quite good. And the comet in the morning twilight has been fun to photograph.

Comet C/2023 A3 (Tsuchinshan-ATLAS) and Ashurst Lake, Flagstaff, Arizona.

I have taken photos on five different mornings over a nine-day period and have captured images of the comet growing brighter and the tail growing longer. On only one occasion was I able to see the comet with the unaided eye. On three occasions I was able to see it with binoculars. On all five mornings it was very easy to capture the comet with even very short exposures on the camera.

The comet is now getting very close to the Sun so I have suspended photography for a few days. When it reemerges in the evening sky I will once again start shooting photos. I hope it is easier to see during this phase.

I shot the comet with a few different focal lengths (50mm, 85mm, and180mm). I think the best images were with the 85mm f/1.8 lens (usually shot at f/2.8) as it gave a wide-enough view to include some foreground.

Here are some photographs and time-lapse video from the period 25 September through 03 October.

25 September 2024

This was my first attempt to photograph the comet. It was taken from the overlook on Mars Hill, home of Lowell Observatory, in Flagstaff. The comet is small and located in the upper middle of the photograph. I often shoot photos of astronomical objects in the eastern sky from this location because I can include much of the city.

26 September 2024

I was planning on returning to Mars Hill but smoke from a managed wildfire suggested I should try elsewhere. I ended up at the Mormon Lake Overlook. The first image is a stack of 16 images taken over the course of about five minutes. The stacking increases the signal, reduces noise, and allows more stretching of the histogram to pull out the faint details.

The video was taken from the same set of images but without any cropping. The camera was mounted on a star tracker so that the comet remained fixed in the images.

A stack of 16 images taken over the course of about five minutes. (26 September 2024)

Time-lapse video of the comet rising above the eastern horizon. (26 September, 2024)

28 September 2024

With some smoke still present I returned to the Mormon Lake Overlook on this morning. I was disappointed at the clouds but afterwards decided that I really liked the image of the clouds partially obscuring the comet tail.

October 01 2024

I went to Ashurst Lake for this photo session with the hopes of catching a reflection of the comet tail in the calm waters of the lake. I was not disappointed!

In the first image, the comet has not risen above the horizon but the comet tail is strikingly visible in the sky and reflected in the water. In the second image, the comet has barely cleared the trees, the tail is still quite bright, but the reflection on the water has dimmed. Next, the waning crescent Moon rises–and is partially behind a cloud–as the sky brightens making the comet’s tail more difficult to see. The final image is a stack of six images and cropped to show only the comet and tail.

The tail of the comet is reflected in the still waters of Lake Ashurt, near Flagstaff, Arizona. (01 October 2024)

The comet has risen above the trees and the tail remains strikingly visible while the reflection has dimmed.

The crescent Moon joins the scene in the eastern twilight. The sky has brightened making it more difficult to see the tail. (01 October 2024)

Close up of the comet and tail in the bright twilight. (01 October 2024)

October 03 2024

My goal on this morning was to shoot a long sequence of images so that I could produce a time-lapse video starting when the comet was below the horizon until twilight became too bright to see the comet. Again, I was at Ashurst Lake hoping for reflections or smooth water. Success!

The first image was taken ~14 minutes before the comet rose above the horizon but the tail is still easily visible.

The comet is below the horizon but the tail extends well up into the twilight sky. (03 October 2024)

Time-lapse video of the comet rising during the period 0503–0533 MST. (03 October 2024)

As I mentioned at the beginning, there have been many articles about the comet. I think this one from Sky and Telescope is one of the better ones. Also, EarthSky.org has published many beautiful photos of the comet.

The best is yet to come!

North America Nebula and a Meteor

August 2, 2024

We had a break in the summer monsoon resulting in several nights of clear skies. I took advantage of the weather to do some astrophotography. I had a few targets in mind and settled on the North American Nebula and Pelican Nebula located in the constellation of Cygnus.

North America Nebula in the constellation Cygnus.

I ended up at Sunset Crater Volcano National Monument because of the very dark skies there (they are an International Dark Sky Park) and because of the nice parking lot for setting up the photography gear. Once everything was set up, I pulled out the camp chair and relaxed looking up at the sky while the camera was busy taking photos. While staring at the stars I saw a bright meteor move through the constellation Cygnus. Checking the camera I was happy to see that the meteor had been completely captured in the field of view.

I captured 77 images each 60 seconds in duration. After grading the images I ended up with 70 usable images for stacking. I used Starry Sky Stacker for the alignment and stacking and rnc-color-stretch for the post processing to bring out the colors and detail.

I’ve taken photographs of the North American Nebula twice before (2019, 2020) but this was the highest quality set of images and it had the meteor. A successful evening.

Nikon D750, Nikkor ED 180mm f/2.8 AIS, 70×60 seconds, ISO 1600, f/4.

Sedona Moonrise–June 2024

July 2, 2024 / 1 Comment

It is the season for capturing the nearly-full Moon as it rises behind Cathedral Rock in Sedona, Arizona. The best time to capture this is a day (or two) before the actual full Moon so that late afternoon sunlight still illuminates Cathedral Rock. The Photographers Ephemeris (TPE) was used to determine the best location to shoot this as it became visible between the towers.

Unfortunately, there was a major dust storm the day and dust remained in the air partially obscuring the Moon at lower elevation angles. The Moon got brighter as it rose higher in the sky.

The nearly full Moon rises behind Cathedral Rock in Sedona, Arizona.

And here is a time-lapse sequence of the Moon rising.

Time-lapse sequence of the Moon rising behind Cathedral Rock.

Bonus:

Here is additional Moon photograph taken at Upper Lake Mary near Flagstaff in early June. I was going for the reflection.

Moonlight reflected in Upper Lake Mary from a crescent Moon.

Milky Way and a Fisheye Lens

June 11, 2024

I have taken countless photographs of the Milky Way using anything from ultrawide to telephoto lenses. But I have never taken a photograph of the Milky Way with a fisheye lens until now.

The Milky Way along with bands of airglow stretch across the eastern sky.

I like the result because it shows a large part of the Milky Way from south of the Galactic Center northward almost–but not quite–to Cassiopeia. Cygnus can be seen in the center.

As a bonus there is some banded airglow along the eastern horizon.

SpaceX/Falcon 9 De-Orbit Burn–III

June 5, 2024

Here are a few more SpaceX Falcon 9 deorbit burns observed over Arizona during the latter half of May.

SpaceX Falcon 9 second-stage deorbit burn on 31 May 2024.

SpaceX has launched frequently during this time period and many of the flights pass over the southwest United States and Arizona. The timing of the deorbit burn is fortuitous as it occurs just as the 2nd stage of the rocket appears above the western horizon and continues until it is near the zenith. This results in very favorable conditions for taking photographs and video of the event.

SpaceX Falcon 9 second-stage deorbit burn on 23 May 2024.

SpaceX Falcon 9 second-stage deorbit burn on 22 May 2024. This is a 1-second exposure with 80mm telephoto lens.

SpaceX Falcon 9 second-stage deorbit burn on 22 May 2024.

I have used both ultra-wide angle and fisheye lenses and really like the result from the latter as it is able to capture the lake reflections as well as the entire burn even as it passes overhead. One time I used a short telephoto (80mm); I may try this again.

Some of the images use 30-second exposures while others use a very short 2-second exposure which is useful for creating time-lapse video.

Time lapse video (2-second exposures) of the SpaceX Falcon 9 deorbit burn.

It’s interesting how all the image and videos show a burn that ends as it approaches the zenith followed by a splash of color as it moves overhead and leaving a circular red patch in the sky. It’s possible that the red is from the chemical reaction of the exhaust gases with the ionized air in the ionosphere. This red coloring of the ionosphere has been noted before with launches ascending into orbit so it is possible that the same chemical reaction takes place on descent.

Additional images of SpaceX Falcon 9 deorbit burns: 13 April 2024; 02 May 2024.

Flagstaff Altitudes

Category: Astronomy