Sun Features through Baader Astrosolar film and Filters

chrisyeo · Post by **chrisyeo** » Wed Jun 09, 2004 4:15 am

I was viewing the Venus transit at 1:30pm with a 90mm etx and Baader Astrosolar film with a yellow filter and I noticed something that I previously had not noticed before.

Besides the two small sunspots, there is a grainy texture across the whole centre of the sun. This is only obvious with the yellow filter.

I started switching colour filters and in the green and blue ones, a feature in the 2 o'clock position became obvious. You know those documentaries that show flowing lava? Sometimes there are cooled patches of lava surrounded by a ring of bright glowing lava? There was a region on the sun that reminded me of that. It had brighter lines circling a darker patch. The region was quite large, stretching from the 1 o'clock to 2 o'clock position.

I had thought previously that Baader film can only show sunspots, but not surface detail. But perhaps it's just that my scope is too small. Does anyone else observe with Baader film and has seen these things before? Can someone confirm these features I've observed?

Cheers,
Chris

harlequin2902 · Post by **harlequin2902** » Thu Jun 10, 2004 2:26 am

Hi Chris,

From your description, I think these are what you saw. They are common sights during solar observing :

http://zebu.uoregon.edu/~js/glossary/faculae.html

In Toa Payoh on Tuesday, we did observe some near the edge of the Sun with a yellow filter too.

More about solar features can be found here :

http://science.nasa.gov/ssl/pad/solar/feature1.htm

chrisyeo · Post by **chrisyeo** » Thu Jun 10, 2004 12:43 pm

Thanks.

Is the grainy surface I saw granules then? Can baader film see that?

Chris

harlequin2902 · Post by **harlequin2902** » Thu Jun 10, 2004 1:11 pm

Hi, yes, granulation can be seen with solar filters.

Post by **weixing** » Thu Jun 10, 2004 1:52 pm

Hi,
I think I also saw the granules... Also, I check the image I take, I found there are grain like "thing" on the sun in the image... I wonder is that noise of the camera or granules??

Have a nice day.

chrisyeo · Post by **chrisyeo** » Fri Jun 18, 2004 4:52 pm

Finally.. ! I knew there would be a photo somewhere that would show what I saw.

Zongye posted this photo of the transit:
http://www.geocities.com/swat_pup6433/tranist.JPG

The feature I saw is centre left in this photo, a barely discernable patch that has bright filaments. It is much more obvious using the colour filters.

Chris