Observing near the edge!

The posts that I’ve made about what happens during the eclipse assume that you are fairly deep within the path, and get at least a couple of minutes of totality. 

What about the people who live within the path, but close to the edge? Or what if you planned to be fairly deep within the path, but clouds in that area forced you to be at an area close to the edge of the path?

This post is designed to help you make the most of being near the edge of the path of totality, if by choice or if other factors made you end up there.

I refer you to this map: http://xjubier.free.fr/tse2024map 

Remember when you click on the map and look at the circumstances, you want to pay attention to the “lunar limb corrected” duration of totality. Being close to the edge of the totality path does resort in a shorter totality, but you get an extended duration of certain features. 

Baily's Beads

The Baily’s Beads referred to in my checklist post last for a few seconds when you are deep into the path. From closer to the edge, the beads last noticeably longer. (Remember that in order to see the beads properly, you have to have a safe solar filter over your eyes.) If you want to get a better view of the beads dancing along the edge of the moon just before totality, and right after totality ends, near the edge of the path is the place to go.

Here are some videos showing Baily's Beads:

https://www.youtube.com/watch?v=mRjpAtSgypE

(near the centerline in 2017- beads are best seen at 2:10 to 2:20)

https://www.youtube.com/watch?v=hZLRqPCF3_g 

(at an annular (95% ring of sunlight) eclipse in 2023: beads are best seen from 1:15 to 3:15 (but he was RIGHT at the edge!)

Remember, at this eclipse, just before totality, ONLY the beads would show, and not the rest of the sunlight. Remember that being RIGHT at the edge of totality risks missing totality altogether! I'd recommend going at least several miles into the path.

Chromosphere

Right at the beginning and end of totality, the chromosphere: a thin, red layer of hydrogen gas becomes visible at the edge of the sun. Once again, when an observer is deep in the path, the chromosphere is only visible for a few seconds at the beginning and end of totality. But from close to the edge, this beautiful feature is visible for a longer period of time. 

Shadow bands

There are also the shadow bands referred to in my other post. They are faint ripples of shadow that move along the ground. These are believed to be caused by the thin crescent sun shining through turbulent layers in the Earth’s atmosphere.

Therefore, they are more likely to be visible with the sun is a very thin crescent. From deep within the path, the sun is a thin crescent for just a short time. Close to the edge of the path, the sun is a thin crescent for a longer period of time. Shadow bands have a better chance to be seen for longer from the edge.

(Even then, shadow bands are relatively rare, so don’t get your hopes up!)

These features are quite striking. Some people purposely go close to the edge of the path so that they can get a better view of these features! This comes at a sacrifice of totality duration, and the view of the corona is shortened, but people who purposely go close to the edge believe that the gain of these other features is worth it.


Next post: A website that simulates the eclipse so you can get an estimate of how long the Baily’s Beads and chromosphere may last at your location!





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