Eclipse sequence

Annular Solar Eclipse of 14 October 2023

(Click on any image on the page to see a larger version.)

Annular eclipses occur because the Moon isn't in a perfectly circular orbit around Earth, and the Earth isn't in a perfectly circular orbit around the Sun. This means that the angular sizes of both bodies vary slightly. If a solar eclipse happens when the Sun is a bit nearer, or the Moon a bit farther, the Moon might not fully cover the Sun at totality. In that case, we will see a ring (an "annulus") around the Moon, and it won't get dark enough to see the corona. While not as impressive as a total eclipse, it's still very pretty. These are commonly called "ring of fire eclipses". This little imaging expedition was a good dry run for the bigger trip to record the 2024 total solar eclipse in the U.S.

On Saturday, October 14, 2023 an annular solar eclipse traced a path southeast from the Oregon coastline, down through Nevada, Utah, New Mexico, Texas, and then through Central America and northern South America, exiting into the Atlantic. I had intended to travel east of Albuquerque to image this event (not far from where I saw another annular eclipse in 2012), but I had some concerns about possible clouds, so I went instead to the Bisti/De-Na-Zin Wilderness, south of Farmington, where I had perfect weather conditions. The event spanned about three hours, from 9am to 12pm local.

I arrived a little before dawn, allowing me time to set up my telescope while I could still see Polaris and achieve good polar alignment. I used the same equipment that I did for the 2017 total solar eclipse in Wyoming: a Canon 7D camera on a Stellarvue 102A refractor riding on an iOptron CEM25P equatorial mount, and to shoot a wide field sequence, my old Canon 300D with a Samyang 14 mm wide angle lens. Both instruments were fitted with custom solar filters.

At annularity (when the Moon was centered in front of the Sun), the lighting became very odd. Besides being darker outside than felt right for the height of the Sun, and a significant drop in temperature, shadows were strange. This is because they were being cast by a ring of light, not a disc like usual. Note the crescent-shaped image cast by the "pinhole" my hand made in the shadow selfie below.

Equipment setup Shadow selfie

Below we see the sequence of the eclipse in 5-minute slices, both through the telescope and in a single widefield composite.

Telescopic sequence Widefield sequence

The Sun is very active right now, and we can see several prominent sunspot groups on its face.

Sunspots

Animated sequence, from the beginning of the eclipse to the end.