Saturday, March 29, 2008
Prominences and filaments
Today I went outside with my Coronado PST to do a little solar observing. I observed for about one and a half hour and from 13.50 until 14.20 local time I made a sketch of the Sun using different Red, Yellow, Orange and Grey soft pencils. The paper I used was black sketching paper. I also used three different erasers. As a smudging tool I used my finger. The technique I used was adapted from the book "Astronomical Sketching" by Handy et al. The picture below shows the result I got from my observing session. Overall I counted three groups of three prominences each. One on 3 o'clock, another on 4 o'clock and the last between five and 6 o'clock. On 9 o'clock I detected a lonely prominence. On 3 o'clock I saw two prominences that were completely detached from the solar disc. The same goes for two prominences at almost six o'clock. In the 4 o'clock group and the six o'clock group I saw two prominences looking like a mushroom. I think they are called "hedgerows" by official classification. I also found two filaments. One was a dark "S" formed structure about 1 o'clock; the other was a small half circle around a much lighter pelage at 5 o'clock.

The sketch was made using a low cost 15 mm Ultrawide (66 degrees) eyepiece with long eye-relief from Sky watcher. The picture was much clearer and showed more detail than my 15mm Vixen Lanthanum. The latter is absolutely darker, and much more expensive (about 5 times the price of the Skywatcher 15mm). Other eyepieces that were used during observing were the 21mm Denkemeier, 12 mm Nagler T4 and the 9mm Ultrawide from Skywatcher. I hope the Sun will start showing a little more details in the H-Alpha band in the next few months. I really enjoyed the H-alpha sketching. It makes you look very careful for details.


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Posted by Math on 03/29 at 03:32 PM | (0) Comments | filed in: Solar log | Print