Total Solar Eclipse of 8 April 2024

On Monday, April 8, 2024 a total solar eclipse tracked across the mainland U.S. on a path from Texas to Maine. I witnessed and imaged this event from northern Arkansas.

Not unlike the total eclipse that crossed the country in 2017, this event was widely publicized and increasingly dominated the news in the last month or two before it occurred. The path crossed many major cities, and there were predictions of massive traffic jams as millions of people sought the path of totality. There were also dire predictions of infrastructure collapse as cellular communications and emergency services were overwhelmed. Little of this came to pass (outside of fairly localized traffic backups in some places once the eclipse was over).

Although I had been planning on seeing and imaging this eclipse for years, less advance preparation was required than in the past. I used the same equipment and procedures I developed for the 2017 total solar eclipse and for the 2023 annular solar eclipse. Mainly it came down to deciding where to go for it. I assumed someplace in southwest Texas, near the Mexican border, as all the weather predictions and statistical history pointed to this area as the least likely to have clouds. But starting around two weeks before the eclipse, when weather predictions start being at least slightly reliable, Texas looked increasingly bad. And as the eclipse got closer and closer, most of the path looked bad. Three days before the eclipse I reset my plans and decided to aim for the Missouri/Arkansas/Illinois section of the path. The weather still didn't look great there, but probably the best chance (at least without going to the far northeast, which was outside my driving range). So two days before the eclipse I drove just west of Springfield, MO, where I have friends, spent the night there, and on the following day meandered south through the Ozarks (with beautiful Spring weather) and ended up in the little town of Evening Shade, Arkansas. Following my GPS, I drove just north of the town and found a little dirt road leading to a church about four miles off the highway. That's where I ended up, in a 19th century graveyard with a great view to the south, and just 100 meters from the eclipse centerline.

Equipment setup

Instrumentation: I used a Canon 7D camera on a Stellarvue 102A refractor riding on an iOptron CEM25P equatorial mount. The telescope was fitted with a 0.8X reducer/flattener, giving an effective focal length of 571 mm and a field-of-view of 2.2° x 1.5° (about 4 x 3 solar diameters). I designed a full aperture solar filter for this scope which I produced on my 3D printer. My imaging plan was to use an intervalometer to make a shot every 30 seconds from just before first contact to totality, at which point I'd remove the solar filter and activate a bracketing sequence in the camera (using the firmware add-on Magic Lantern) ranging from 1/4000 second to 1 second in nine 1.5 EV steps. After totality I'd replace the solar filter and restart the 30-second intervalometer sequence until after final contact. A setup error caused the bracketed sequence to miss the longest exposures, so my corona images aren't quite as deep as they could be. But largely an imaging success.

One issue I had to prepare for was making an adjustment to the telescope pointing in the middle of the first partial phase. This is because the eclipse began on the east side of the meridian, and ended on the west. The nature of the equatorial mount carrying my telescope limits its ability to track very far across the meridian without being manually flipped to the opposite side. I lost a couple of minutes of images during this flip, which you may see in the animation below as the Moon gets near the central sunspot.

The Sun

Monday morning dawned largely clear, with only a very thin, high haze and persistent contrails that spread into thin clouds. Nobody else was around. While I was setting things up, some folks I had met there the previous day drove over with a hot breakfast for me, which was much appreciated! I got the telescope tracking on the Sun without difficulty. I had set up the mount the night before and used Polaris to polar align it, which is much easier to do when the stars are out. Not long before the eclipse began, a couple from Michigan came by, and one local woman. That was the extent of the crowds.

This was the appearance of the Sun shortly before the eclipse began. Solar activity was high, which usually means an abundance of large sunspots. However, the sunspot activity on this day was pretty low. But the activity of the Sun was certainly reflected in the many large prominences that became visible during totality.

View at totality

As first contact approached at 11:36 am CDT, I started the camera collecting its 30-second sequence. As the partial phase advanced, I was able to casually observe it through a filter as the camera automatically went through its operations. Over the next hour, the quality of the light gradually changed, with the landscape assuming a low-contrast appearance, and the temperature dropped from perhaps 80°F to the high 60s. These effects became very obvious in the last 20 minutes before totality. In the last few seconds before 12:53 pm, it got dark rapidly. Suddenly, it was very dark, with a deep blue-black sky. Venus and Jupiter stood out prominently on each side of the eclipse and a 360° twilight lit the horizons. The dramatic coronal ring around the now hidden Sun leapt out, and several intense red prominences were immediately visible. Beautiful! I removed the solar filter from the telescope and started the fast bracketed camera sequence while observing all of this. In the sudden darkness, I was surrounded by the sound of crickets, and a distinct shift in bird sounds. Totality lasted over four minutes, and the full eclipse didn't end until 2:13 pm.

This image is just a quick snap with my phone camera, and comes pretty close to capturing the visual appearance of the event. Note the twilight sky above the horizon, lying beyond the 90km radius of the Moon's shadow. Venus is visible below and left of the eclipse. Jupiter is outside the frame to the left. A gravestone is poking up at the bottom right.

HDR image of corona

This is a highly stretched, high dynamic range image of the corona, compressing a very wide intensity range. It was constructed from seven images exposed from 1/30 second to 1/8000 second.

Totality sequence

This sequence of seven shots is aligned on the Sun, so we can see the shift of the Moon over nearly four minutes, from just after the start of totality until just before its end. Note the significant amount of coronal activity and the large prominences along the edges. It is clear that the Moon's apparent size is larger than the Sun's, which is what made totality very long. This is just the opposite of what occurs with an annular solar eclipse, where the Moon is smaller and never completely covers the Sun at all. On average, the Moon and Sun are almost exactly the same size in the sky, but because the Moon's orbit is slightly eccentric, its distance (and therefore apparent size) changes a little.

An animated sequence, from the beginning of the eclipse to the end. Frames are 30 seconds apart and span 2 hours 40 minutes. We see the eclipse here at over 500 times its actual speed.