Four Planets in the Morning Sky

March 25, 2020 / Add comment

For several weeks the planets Mars, Jupiter, and Saturn have been visible in the same portion of the morning sky. These are all bright and easily visible even during twilight hours. Nestled in between these bright planets lies the minor planet Pluto.

Stellarium star chart showing positions of the planets in the morning sky.

So I thought it would be interesting to photograph Pluto. Pluto is much too faint (currently Mag. 14.3) for me to find with my camera/lens setup. However, Pluto and Mars passed very close to each other (~10 arc minutes, or less than the diameter of the Moon) on 23 March 2020 making it easier to find one based on the location of the other. Clouds forced me to shoot this image a day later on 24 March 2020, when they were farther apart.

Stellarium chart showing Pluto and neighboring stars.

I used Stellarium as a guide to hopping from one star to another—comparing the photographs with Stellarium star charts—until I finally located Pluto. As a magnitude 14.3 object, this was near the limit of what could be resolved with my Nikon 180mm AI-s ƒ/2.8 lens shot wide open.

Images were shot at ƒ/2.8, ISO 1600, and 30s. The best images were stacked to reduce noise. Post processing included large values of Unsharpen Mask to help sharpen the dimmest stars and Pluto—with the undesired side effect of creating halos around the brighter stars.

Check the video to see how much Mars moves in just 15 minutes.

I was able to capture four planets in the morning sky. In the previous post, I was able to capture four planets in the evening sky. It was a challengin project that I wanted to do and have now completed.

Maybe I should get a telescope.

Oh, one final point. Once again I was photo-bombed by a cluster of Starlink satellites. Sadly, the day is coming soon when night photography will be very difficult because of these satellites.

Objects in the Night and Twilight Sky—February 2020

March 4, 2020 / Add comment

The past few weeks have offered numerous opportunities for photographing objects in the twilight and night sky.

Above is a photograph showing the planets Venus (visible near the top of the image) and Mercury (located just below the center of the image). The glow of evening twilight on the horizon is reflected in the shallow waters of Mormon Lake.

Taken later on the same evening is a photograph showing four planets and an asteroid in a single frame. This was taken with a 24mm focal length lens to capture these solar system objects (SSO). I did this as a fun test to see if a wide-angle lens was able to capture these dim and distant SSOs. From top to bottom are the asteroid Vesta, Uranus, Venus, Neptune, and Mercury.

Zoomed-in crops (below) show the dimmer objects that are in the image above.

Zoomed in crops showing Vesta, Uranus, and Neptune.

Before leaving that night I did a final wide-angle shot of the southeastern sky which included the constellation Orion as well as a portion of the winter Milky Way.

The following night I was out again to test my recently purchased Nikon 180mm ƒ/2.8 ED AIS manual focus lens. A few previous tests have shown that star images are pretty good at an aperture of ƒ/2.8 but much better at ƒ/4. At ƒ/2.8 there is just a hint of star spikes; at ƒ/4 they are quite prominent. This is a stacked sequence of images of the Pleiades star cluster. Image stacking was done with Starry Sky Stacker; histogram stretching was done with rnc-color-stretch.

On 18 February there was a Lunar occultation of the planet Mars. I had planned to get up early and drive to a dark location but an alarm failure meant I barely had time to get up and set up the gear on the rear deck of the house to start the sequence. Luckily, Flagstaff is a Dark Sky City and it was dark enough to get the shots. This is a sequence from just a few minutes before the Moon moved in front of Mars followed by a longer sequence after it reappeared.

Finally, Comet C/2019 Y4 (ATLAS) is in the northern sky making it an easy target—except that it is still very dim with a magnitude of about +12 at the time of this image. The still image is a stack of 49 images each 120 seconds duration at ISO 1600, 180mm, and ƒ/2.8. As noted above this lens is pretty good at ƒ/2.8 but better at ƒ/4. Because the comet is so dim I wanted the maximum light gathering ability so settled for an aperture of ƒ/2.8. Also in the image is M97 (“Owl Nebula”) and M108 (“Surfboard Galaxy”). The star Merak is part of the “Big Dipper.”

Also, there is an animation—made from the same images—showing the movement of the comet over a period of just under 2 hours.

Pictures from the Parks

February 11, 2020

National Parks, that is. Here are several photographs taken this winter in the National Parks and Monuments that are in northern Arizona.

Sunrise at Wukoki Pueblo, Wupatki National Monument.

These two images were taken shortly after sunrise at Wukoki Pueblo in Wupatki National Monument. A recent snowstorm had brought snow to lower elevations and I was hoping there would be some snow at this location. No snow but the sunrise was still pretty nice.

Later that morning in Sunset Crater National Monument, where there was new snow, a small amount of snow on the namesake crater helping to reveal its subtle textures.

Low clouds and fog near the Unkar Delta in Grand Canyon

The next two images are from Grand Canyon National Park at sunrise. A recent minor storm had left some low clouds and fog in the lowest reaches of the canyon. As the sun rose higher and the canyon walls warmed the fog was lifted up and out of the canyon producing some eye-level clouds for a brief moment.

Moonrise over North Rim of Grand Canyon.

Finally, we have a panorama of the rising nearly-full Moon in late afternoon. Wonderful!

Venus and Neptune in the Evening Sky

February 5, 2020

In late January, the easily visible planet Venus was located in the same part of the evening sky as the dimmer and distant planet Neptune. I’ve never tried to photograph Neptune but this pairing of the planets was a good reason to do so.

Venus and Neptune in the evening sky (2020-01-28).

The first attempt was taken on the evening of 27 January (shown below) and I was limited to very short exposures as I was using a standard tripod. The second attempt was the following night from a better location and, more importantly, I was using my equatorial mount star tracker so that I could follow the stars (or planets) for longer exposures.

The image at the top is the second attempt. High, thin cirrus clouds were beginning to move in from the west and I was hoping that the clouds might make some of the stars more colorful. What I got was an amazing corona surrounding the very bright planet Venus while stars and the dimmer Neptune appeared relatively unchanged.

Venus and Neptune in the evening sky (2020-01-27).

The image above is from the first night of shooting and shows diffraction spikes around Venus. Examing these two images you can easily see how far Venus has moved in one night by comparing the position of Phi Aquarii (φ-Aqr).

Andromeda Galaxy – M31

January 26, 2020

I’m still testing out the new-to-me Nikon 180mm f/2.8 ED AI-S manual focus lens. Weather has been the limiting factor but I did get a chance to shoot for a few nights.

Satellite imagery suggested that I might get about an hour of clear skies a few nights ago so I found myself at Sunset Crater National Monument—a Dark Sky National Park. The clouds moved in a bit faster than expected so I only got a few exposures before thin clouds moved across my target in the sky —Andromeda Galaxy (M31). The thin clouds resulted in slightly enhanced color in the vicinity of the brighter stars. Art vs. accuracy. Hmmm… In this case, I like the art version.

The previous night I had also attempted this shot but the lens would not maintain sharp focus. It turns out that when pointed up at an extreme angle the focus ring slips. I remembered reading about this and a quick search online brought me to this article on the Cloudy Nights website.

It turns out there is a cheap solution (free) and an elegant ($$$) solution. I tried the cheap version and it works but I’m intrigued by the other solution as well.

Above is another version of M31 taken about 10 days earlier when the object was lower in the sky and the lens did not have slippage issues. This is a single 2-minute exposure that has been histogram stretched using rnc-color-stretch.

Finally, I tried shooting the Orion Nebula (M42) recently but the shot was “photo-bombed” by the SpaceX Starlink cluster.

This is going to be happening more as SpaceX and other companies launch tens of thousands of these small satellites into Low Earth Orbit over the next few years.