Fine example of the Wilson effect

[Stu]

There appears to be a new AR on the limb of the Sun just now and it is demonstrating the Wilson effect t nicely I think.

It appears as a bright white line, but with the tiniest sliver of black along the side further from the limb. My assumption is that this will broaden out into a large spot with umbra and penumbra but worth watching as it comes around the limb now and in the morning. It’s at about two O’clock refractor view right now.

[Knighty2112]

Well, was supposed to be nice and clear here this afternoon and tonight, but so far still pretty much wall to wall cloud otherwise I’d have a crack at it. 

[Stu]

I didn’t manage a look today unfortunately, was busy with other things and then it clouded over.

[John]

One of my 1st astro observations and sketches was of the Wilson Effect on a sunspot. Made with my 60mm refractor and solar projection nearly 40 years ago 🙄

 

 

[Stu]

9 minutes ago, John said:

One of my 1st astro observations and sketches was of the Wilson Effect on a sunspot. Made with my 60mm refractor and solar projection nearly 40 years ago 🙄

 

 

Nice one John 👍. Yesterday’s was even finer than that; just a tiny sliver of black. Shame I missed it today.

[niallk]

Never heard of the Wilson Effect before - 👍👍  Unfortunately cloudy here 🙄

[wookie1965]

Absolutely roasting here and being a red head I'm not going out I'd need a radiation suit. 

[IB20]

Had no idea it was called that; I have seen it on numerous occasions where a sunspot on the limb gives an appearance like it’s depressed into the surface. Every days a school day on here! 😃

[Stu]

10 hours ago, IB20 said:

Had no idea it was called that; I have seen it on numerous occasions where a sunspot on the limb gives an appearance like it’s depressed into the surface. Every days a school day on here! 😃

Exactly that 👍, and the foreshortening gives a real sense of the Sun being a sphere not just a flat disk.

I learn things all the time on here, good innit!