I saw and photographed comet Tsuchinshan-ATLAS (C/2023 A3) last night.
Having emerged from the sun’s glare, Friday, Oct. 11, was the first chance for observers in the northern hemisphere to see it about 45 minutes after sunset (get your sunset time here). So I got myself to a place where I could see low down to the western horizon, where the sun had just set. I spent 30 minutes scanning the horizon with a pair of binoculars, but with so much cloud concentrated there, I had to give up an go home.
How To Find And Photograph The Comet Tonight
So I went back to the same place at the same time on Saturday, Oct. 12. This time it was much easier because the comet is rising. I knew from research that it was due-west, halfway along a diagonal line between two bright lights in the sky — the planet Venus in the southwest and bright star Arcturus high above west-northwest. Arcturus is the lowest star in the Y-shape of stars in the constellation Boötes.
It will be about 4-8 degrees above the western horizon, depending on where you are.
What The Comet Looks Like
This time, I found it after only a minute or so spent searching the sky with binoculars. I couldn’t see it with the naked eye, but someone I was observing with could.
After observing it — and its faint tail — I got my camera out. Although it was visible in a clear sky, comet Tsuchinshan-ATLAS was not only close to the horizon but sinking fast in the fading twilight. I had to act quickly.
I got my camera out and put it on a tripod — an essential piece of equipment because I knew I would have to take a long exposure image to capture the comet.
How To Photograph The Comet With A Camera And A Smartphone
Using a DSLR camera with a 105mm lens, I used these settings: ISO 800, an aperture of f4 and a shutter speed of two seconds. The image just about shows the tail, though I couldn’t see much of it through binoculars.
Not two minutes later, the comet was hidden behind clouds and, in any case, sinking quickly into the horizon as the skies darkened.
A two-second exposure for a DSLR means the comet should be relatively easy to photograph with a smartphone. It’s best to use a tripod (or, if not possible, place it on a hard surface to keep it as still as possible) and to focus on a bright star or the moon. Your smartphone’s “night mode” (or similar) will likely take care of how long the exposure needs to be.
Why You Need To See The Comet Soon
Should you go out to see and photograph the comet tonight? Absolutely, because the best is yet to come.
Tonight, only will it be a few degrees higher in the sky, but as a consequence, it will be in the sky for a little longer. That’s going to apply for the rest of the month, but it’s the next few days — tonight, Monday, Oct. 14 and Tuesday, Oct. 15 — that are predicted to be the best nights to see and photograph this icy space rock on its once-in every-800-centuries trip to the inner solar system.
Check my feed each day this week and next for a daily “comet tracker” with essential sky charts and tips for viewing and photographing the comet.
Wishing you clear skies and wide eyes.