Preparations for the Annular, er, Partial Solar Eclipse!

Tomorrow's the day! As mentioned in my last post, tomorrow an annular solar eclipse is visible across a stretch of the western half of the North American continent. 

For the rest of the country - including Dallas where I live - we won't get to see the Ring of Fire but we'll still get to observe a partial solar eclipse. 

Screen shot from Stellarium

Here is what the Sun will look like at maximum eclipse for Dallas (about 11:52am local time). Although that area blocked by the Moon in this simulation looks blue, keep in mind that this is a new moon which means we don't see any illuminated lunar surface since the Moon is in between us and the Sun. 

While you would think that with this much of the Sun covered up the amount of light we see would be low enough to be safe to view without eye protection, it's not! Except during the totality phase of a total solar eclipse when the Moon is completely blocking the solar surface, it is not safe to look directly at the Sun. If you are interested in seeing the eclipse tomorrow, only do so if you have a set of solar eclipse viewing glasses from a reputable source. If you don't already have eclipse glasses it may be too late to get some but here is information from NASA on safe viewing resources. 

Personally, I am treating this eclipse as a trial run for the total solar eclipse that will pass over North Texas on April 8, 2024. I plan to capture the partial eclipse from start to finish using my Nikon D750 and EvoStar 72ED refractor telescope with solar filter mounted on my Star Adventurer tracker. I'll leave it running from well before the eclipse through past the end of the eclipse, capturing a couple of shots a minute. Hopefully, the result will be a handful of good shots of different stages of the eclipse and possibly a sequence of shots I can use to make a timelapse video of the eclipse from start to finish. 

A lot has to happen for this to be successful - a good polar alignment of the telescope the night before, being able to get a good focus of the Sun once it peeks above the trees, the weather forecast being accurate (i.e., no clouds) - but even if it doesn't work out as planned, it will still be good practice for April!

Here are shots of my equipment set up for a test run today. 

That solar filter is critical for
safely photographing the Sun!

The tracker keeps the telescope pointed
at the Sun as it moves across the sky.

I hope you get to see the eclipse, too. Just be sure to be safe when viewing the Sun!

Countdown to Annular Eclipse

Sequence from 2012 Annular Solar Eclipse
Photo by Nathan Eaton

We are just a month away from the next solar eclipse! On October 14th, 2023, people from the upper west coast down across Texas and in parts of Central and South America will have the opportunity to see an annular solar eclipse. As with all solar eclipses, this one involves the Moon passing between the Earth and the Sun. This time, the Moon will be farther out in its orbit around the Earth, making its angular size just a bit smaller than that of the Sun. In such a case, the Moon doesn't quite cover the face of the Sun. Consequently, at mid-eclipse viewers along the centerline of the eclipse track will get to see the Ring of Fire, a view in which the Moon is centered over the Sun with a fraction of the solar surface showing all round the Moon. 

The image sequence above is one I took during an annular eclipse in 2012 when we were visiting Albuquerque, New Mexico. Shot with a Nikon D7000 DSLR through a telephoto lens and a Baader film white light filter, it shows the eclipse from near the start at top left as the Moon has begun to cover the Sun, progressing across and down to the Ring of Fire view at bottom left then on through near the eclipse end at bottom right. For that eclipse, the Sun set before the eclipse was over so I wasn't able to get any shots of the final phase. The reason for the yellow color in that last shot is partly because the Sun was close to sunset and partly due to heavy smoke in the atmosphere from fires west of Albuquerque. Basically, the image came out yellow for the same reason a sunset with heavy clouds to the west looks yellowish to reddish; the denser atmosphere with heavy particulates (in this case, smoke) filters out shorter wavelengths, only letting the longer (and redder) wavelengths through. 

To see how close the path of the eclipse comes to where you live and to see where and when you can view it in person, check out Xavier Jubier's interactive map for the eclipse. Click anywhere on the map and it will give you details of the eclipse for that location including when it starts and ends, how long it lasts and how much of the Sun will be eclipsed by the Moon. Note that the path of the eclipse on the map represents the areas where the annular form of the eclipse will be visible. In the Dallas area, we'll experience a partial eclipse since the Moon never moves completely over the face of the Sun from our vantage point. Unfortunately, we won't get to see the Ring of Fire here. 

Where will you be during the eclipse? 

See the NASA eclipse page for more information on this eclipse as well as the total solar eclipse next April. 

WARNING

Be sure to NEVER look directly at the sun without appropriate eye protection. Read up on safe viewing techniques before viewing the eclipse.