Cosmic Serendipity

May 29, 2020  •  Leave a Comment

Lyrid Meteor and the North America NebulaLyrid Meteor and the North America NebulaThis was taken from Brown County, Indiana on a cold, clear, moonless morning of April 22nd at 3:04am EDT with a Nikon D800 DSLR, converted to record H-alpha, and Rokinon 85mm f/1.4 lens on an iOptron CEM25P mount. It is a composite of six exposures, each 30 sec., f/2.8, ISO 1250, post-processed in Adobe Lightroom and Photoshop. All the frames were registered and median-combined, and the frame with the meteor was added back in Lighten mode.
This is by far the best photograph of a meteor I've ever gotten. Not only is it a nice bright streak with a bit of green color at the top (from the copper in the meteoroid vaporized in the upper atmosphere), but in the background is a the North America Nebula, a familiar landscape in the Milky Way, just below the bright star Deneb in the constellation Cygnus. This is a region of the sky familiar to astronomers, nicknamed because of its resemblance to the shape of North America. 

On this night several circumstances converged, but mostly luck prevailed. This was near the peak of the Lyrid meteor shower in late April. It was clear overnight, pretty rare here in Indiana in the spring, and I was trying out some equipment that I still need to exercise to take full advantage of. I'd hoped to get some views of meteors with a camera and wide-angle lens tracking the "radiant" of the shower (the location in the sky from which the meteor trails appear to radiate) and taking a sequence of time-lapse frames.

In the meantime, I was using another camera to take closer views of some interesting locations in the sky, mounted on a more precise tracking drive. This camera had been modified to capture light from glowing hydrogen that is normally blocked in stock DSLR cameras. Because some of the most interesting places in the sky are full of glowing hydrogen, it's possible to modify the cameras to fully capture these views. One such place is the North America Nebula, also familiar to astronomers as NGC 7000 a region of active star formation. It is one of the larger such areas in the sky and a good target for a moderately long lens, 85mm in this case. 

I was pleased with the results I was seeing at the time, but didn't entirely realize what I'd gotten until I was loading the photos from the memory card onto my computer. Looking more closely, I noticed that not only was there the very bright trail, since I had taken several identical frames (to later combine in post-processing to improve the quality) but in two other frames I could see the trail of the meteor fading and distorted by the upper atmosphere wind, the orange glow between the pink nebula and Deneb.

I haven't had a whole lot of good results from watching and photographing meteors. It can be satisfying to get outside at night and just watch the sky for a while. Despite the internet hype though, meteor showers are not usually spectacular light shows. The frequency of meteors does increase during showers, but most of the time there still may only be a few per hour over the whole sky. Things like city lights and bright moonlight usually interfere and you see the flashes of only the brightest meteors, which are rare indeed. 

Here are a couple of examples of one of the best showers, the Perseids that appear in August every year.  I keep hoping for a spectacular show, which does happen occasionally with this shower, but haven't been rewarded quite yet. 

Perseid Meteors above Sprague LakePerseid Meteors above Sprague LakeI was thinking about how to process some night sky results and revisited some photos from the Persied meteor shower last August. I happened to be in Rocky Mountain National Park, usually a pretty good site for dark and clear skies. While I missed the peak of the shower, I was able to get out and shoot the following night while there was still some meteor activity. Sprague Lake provided a nice foreground, the calm air kept the lake glassy smooth to reflect the night sky -- as well as the lights of Estes Park, just outside the National Park to the east. (It's supposedly a good place to see moose, but alas none showed up even at their favored feeding time before sunrise.)

The first photo is a composite of seven frames, each a 60 second exposure (Nikon D850, 14-24mm f/2.8 @ 14mm f2.8, ISO 1600). In all but one frame a mask in Photoshop reveals only the meteor trail. Otherwise the motion of the sky (actually a reflection of the motion of the Earth, of course) would make confusing, trailed star images as in the second photo. The same meteors are there, but overwhelmed by the overlapping star trails totaling about 45 minutes of exposure.

The first one was taken at Sprague Lake in Rocky Mountain National Park a couple of years ago. It's a composite of seven exposures, the ones with meteors out of many frames in a time-lapse spanning a few hours. One of them is a nice bright meteor. I like the night sky landscape even without the meteors, which are a bit hard to see. You may notice that the streaks are roughly radial, looking like they originate from a point in the sky. This is because in reality the Earth is moving through a stream of small rocky fragments along a path in the Solar System that was the orbit of a comet long ago. As we plow through the stream, we see meteors coming at us, their paths foreshortened into short streaks, something like driving through a snow storm. The name Perseids comes from the apparent source of the meteor paths, in the constellation Perseus. Despite the glow on the horizon is from Estes Park, the town just outside the National Park the sky there is quite dark so we see part of the northern Milky Way and many faint stars, even reflected in the calm lake. 

2019 Perseid Meteor Shower2019 Perseid Meteor ShowerEven one day after the peak of the Perseid meteor shower, I was able to capture many meteors over several hours on the morning of August 14, 2019. There may have been many more, fainter ones, but the nearly full Moon illuminated the sky. And this was taken from my patio with a fair amount of ambient light from suburban Bloomington, Indiana.

This is a composite of 34 frames from a stationary camera shooting a time-lapse sequence for about 5-1/2 hours. To compensate for the motion of the sky, the frames were aligned in Photoshop so that the shower's "radiant" and the meteor trails retain their true position in the field. Meteor trails were isolated using a Photoshop mask and superimposed on a single frame to provide the star background.

Nikon D850, 20mm f/1.8, each frame 14mm, 30 sec., f/4, ISO 1000, Pluto trigger.

The second one was taken in my back yard in Bloomington, Indiana last summer. This shows many more meteors despite brighter skies than in the Rocky Mountains because this was closer to the peak of the meteor shower, and likely there were just more meteors that year. Here you can see the radial pattern of the paths more clearly. This too is a composite of many frames from a time-lapse sequence. I aligned the images as well as I could and then used a mask to reveal each meteor streak against a single frame of the starry sky.

But sometimes you just get lucky.



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