Comet C/2020 F3 floats in the predawn twilight sky over Lake Erie. Photo by James Guilford.
C/2020 F3 (NEOWISE) presented special challenges for observing and imaging as it showed up very low to the horizon rising ahead of Sun — not much more than 10º before morning twilight wiped it out. July’s weather around the apparition grudgingly cooperated with relatively clear night skies tarnished by atmospheric haze and bright Moon to light it.
Not having any clear views of the eastern horizon from home or nearby parks, at 3:00 AM, July 9 I set out for the Lake Erie shoreline. It took me about an hour to reach the deserted park where I unloaded my gear from the car and made the brief hike down to a convenient fishing pier. With dark lake waters quietly lapping the base of the pier, I surveyed the barely visible gray horizon. The mood was quiet and a bit spooky. But I had a mission.
Star chart showing the location of C/2020 F3 with named stars labeled. Credit: SkySafari
I saw no trace of the comet and only a few stars overhead. I’d cut my sleep short, made a long journey to get there, so I set up my equipment and hoped for the best. Using a star chart, I estimated (guessed) the location of my target. I set the camera for an test exposure and, at 4:18 AM, tripped the shutter.
At first I thought I’d missed it but, holy smokes! There it was! Faint but in the frame!
The location exposure for Comet C/2020 F3 was, astonishingly, right on target! This image, without enhancement, shows the comet (within the circle) and a few stars above. At that time (4:18 AM) and only 4º above the horizon, it was invisible to the eye even with the use of binoculars.
The position of the comet, close to the Sun and beginning its retreat, meant it would not be long before morning twilight would drown out the delicate view. So I shot image after image, groups of images to “stack,” and waited for my preferred and ideal view: the comet glowing over the lake with the colors of early dawn.
A tight crop of C/2020 F3 as predawn colors begin to tint the horizon. Here, at 4:49 AM, the comet is only 7º above the horizon — but nearly as high as it would climb before dawn. Photo by James Guilford.
I switched from 400mm telephoto to 105mm maximum as twilight began to appear and brighten. Eventually I was able to record the scene I had imagined (top of this page). Not long after, dawn’s early light grew brighter than the comet and it was gone.
On the left is C/2020 F3 processed for a pleasing view. On the right the image has been brightened to show as much of the coma/tail as the camera recorded. The expansive dust trail is detectable here but not the comet’s ion tail. Photo by James Guilford.
I never did see Comet C/2020 F3 with unaided eye. I viewed it several times through my binoculars but especially enjoyed the experience of seeking and capturing images.
The comet returns as an evening/dusk object in about a week. I’m sure I’ll be out after it then, too!
As viewed from Northern Ohio this was not a spectacular cometary apparition, but then how many comets do we see in one lifetime?