Sky & Telescope Answers Your Eclipse Questions: Part II

A few weeks ago we took to Twitter and Facebook to find out what questions you wanted answered about the August 21st Total Solar Eclipse. Now we're back with Part II of the answers! (Part I)

 

Q: How much of a difference will there be between ~95% and 100%? Trying to decide if it's worth a three hour drive.
- @StylusH, Twitter

A: Very different. A total eclipse is a different animal.

 

Q: Is a 2 degree field of view enough to capture corona during totality? Have 8" Dob 1200 mm focal length (f5.9). Thinking about using 40 mm Plossl. Should give 2 degrees.
- Ernie, Facebook

A: Seems like the TFOV of the setup here is closer to 1.5°? Assuming the 40-mm Plossl has a 43° AFOV? The corona could stretch as far as 3.5° (max). So yes, in theory, 1.5° (or better 2°), you could see the corona, but you wouldn't be seeing all the corona. Keeping it narrow would be better to see the corona details and Regulus (about 1° from Sun); going wide, you could possibly see entire extent of corona.

 

Q: What is the safest way to watch the total solar eclipse?
-@JonGrummer

A: During the partial phases of this eclipse, as with any time the Sun is shining, don't look at the Sun directly unless viewing through an approved solar filter. Or you can use indirect projection of the Sun. If you're lucky enough to witness totality, you won't need any!

 

Q: Will it be visible in the southern hemisphere?
-Gerda, Facebook

A: Great question! The total solar eclipse will not be visible in the southern hemisphere, but a partial eclipse will be visible from parts of South America. There's a handy diagram in this article about viewing the partial eclipse.

 

Q: I'd like specific information on where to go to see the best views of the totality phase of the ecliipse. Thank you!
-Odette, Facebook

A: That depends on what you mean by "best." In terms of weather, we have a detailed guide of what to expect for each region, with maps and cloud statistics. (There's also a link at the bottom of the article for downloading it as a PDF.) We also recommend consulting these guides. But remember that many accommodations have completely sold out, so weather considerations aside, the "best" place might be wherever you can find a bed!

 

Q: At what percentage of the Sun being covered by the Moon does the sky become noticeably darker? I'm in the 85% partial eclipse area.
-David, Facebook

A: "Noticeably" darker for a dedicated skywatcher? I'd say at 30% obscuration of the Sun. Casual skywatcher, maybe 75%.

 

We hope you enjoyed these answers to your questions — for more information, visit our eclipse resources page about the 2017 Total Solar Eclipse.