White sunspots

[Scosmico]

Today during my solar observation session I spoted two groups of white sunspots close to the solar limb. This is the first I see them. They are located between sunspot 1519 and solar limb, and between sunspot 1522 and solar limb.

I checked the SOHO site, and found a HMI picture that confirms the white spots.

http://sohowww.nasco...nspots_1024.jpg

I am using a 102 nexstar with a Baader film.

Because I only noticed them today I checked the SOHO database to see if they were there since when I saw the AR1520 for the first time. But they were not there, at least not visible in the SOHO pictures as well.

For the most experienced solar observers, is it correct to afirm that these white spots are only visible when closer to the limb? If this is true, how does it happen?

It is quite interesting that the white spots came to my attention due to some clouds passing in front of the sun.

I put a moon filter to get a bit more of contrast. There was a small improvement in the contrast, but nothing like a clear view like the normal black sunspots.

Does anyone can give me a tip to get a bit more of contrast on those white sunspots? Baader continuum filter?

It will be nice to hear your experience observing those. This is my first week observing the sun!

Thank you

[David Smith]

I use a #56 Green filter (normally associated with planetary viewing) as i find this generally helps to improve contrast. I have also used my Baader Neodymium filter from time to time. I do not have the Continuum filter, have considered it but am not totally convinced it will improve things.

Will be interesting to see what others think of the Continuum filter.

[Moonshane]

I have the Baader Solar Continuum and although I have never used a green filter on the sun I can confirm that after a short period of not really 'getting it' can now see that there's a substantial difference in the detail visible with the Baader. it makes the granulation much more apparent and there's a greater degree of contrast with the sunspots and also the disk generally. it has the added benefit of reducing the glare even with the proper solar filter. one point to note is that as this is a broadband filter it 1) reduces/eliminates chromatic aberration in fast achros and 2) has a highly reflective surface. the latter point means that if you have an eyepiece with long eye relief you will see nothing but your own eye unless you make some kind of eyepiece shield.

I can highly recommend the Baader filter for improving the visual detail of the solar disc.

the white marks are called fasculae and are created by the same processes as the dark sunspots and associated with them. in fact the fasculae apparently create more lighter area on average than the dark sunspots so contrary to what you might think, in periods of high sunspot activity the sun is lighter than when there's no sunspot activity! I generally see the fasculae more at the limb and I think this is typical.

[Scosmico]

I had a very good result today using two filters with my BGO 12,5.

The filters mentioned are my Skywatcher light pollution filter and my revelation 25% #ND96.

The coolest part is the Calcium K look because of the light pollution filter.

I was able to see the granular appearance of the white sun, middle disc included. And see a beautiful fasculae group details close to the limb of the sun.

Other two smaller groups in the opposite limb. As you can see I am still learning how to locate North/south, East/west in the Sun.

The idea to put both filters together came from the clouds that were crossing the sun and enhancing the contrast.