Sun – Page 29 – Astronomy Sketch of the Day

A daisy in the field

What a difference a day makes

This pair of sunspot drawings hails from the tail end of activity of the current solar cycle. The weekend of May 1st and 2nd 2005 consisted of two ‘blue sky’ days here in southern England, and I had the chance to observe and sketch the Sun in white light on both of them, recording the intriguing changes to AR 756 that occurred in just over 19 hours. I used graphite pencil on white cartridge paper, my favourite medium for this kind of target. For each sketch I drew the umbra first, then added the penumbral region with lighter pencil strokes drawn from the umbra outwards, with the pores being added last. The seeing conditions were very steady and not a breath of wind was to be had while I spent a happy (but very hot!) hour in front of the eyepiece each day.

Sally Russell

Sketch details:

Date: 1st and 2nd May 2005

Time: 14.20-15.30 UT & 10.05-11.15 UT respectively

Equipment: 105mm AstroPhysics APO, 9mm TV Nagler, 2 x Barlow (mag x135),

Kendrick white light filter

Additional accessories: Large brimmed straw hat and a cold drink!

Medium: Graphite pencil on white cartridge paper

Each image size: approx. 1.5″ x 1.5″

Fountains of the Sun

Ever-changing Proms

AR949 was not very apparent, but there may have been a hint of a few pores towards the center of the disk, slightly north of the “equator”. There were two long slender patches of plage near a fairly long (maybe 20 deg) filament in this region.

Along the limb, I noted 7 areas of prominences, with some scattered jets of “baby” proms spiking out here and there. Of the 7 areas, I initially concentrated on two, position angles of approximately 240 and 50 degrees. The area at the NE was very faint at first. I adjusted the front etalon to create more contrast. But come to find out, yes it was faint, but the sweet spot of this 60mm Maxscope seems to be just SW of center. I heard that these Maxscopes don’t have a sweet spot, but there is an obvious difference in the contrast depending on where your target is in the FOV with this scope. Still, it’s a beauty of a scope and I still can’t believe my good fortune in acquiring it.

The prominence to the SW was very sharp and prominent. Still, you can see the slight changes over a 30 minute time frame, making it an amazing site to behold. Like the Moon, you can’t spend a lot of time rendering the view. The terminator on the Moon changes before your eyes. Well I feel the Sun is even more dynamic, and the sketches last only minutes before the shapes take a different form.

Getting back to the NE prom, it was very fibrous and to me was lovelier than the SW area. Again, the changes are noted in a 30 minute time frame.

What ended up being my la proéminence du jour was a patch of nearly lunar terminator looking proms on the western limb. When the session began, this area was plain, with only a few little spikes with a finger pointing north. But about 45 minutes later, made me feel like I was observing the Moon again, just like it did the day I sketched this prominence.

AR946 had comma shaped plage surrounding the 2 sunspots within connected by a darker
strand. There was a filament about the same size located to the southern region of
the disk as well as plage just inside the limb about 30 degrees from the prominence
at PA 70 degrees.

2007 04 02, 1900-2000 UT
Zanesville, Ohio
Internally Double stacked Maxscope 60mm with 8mm TV plossl.
Seeing average with moments of heavy quivering. Transparency poor.
Temps 72 °F / 22.2 °C
Winds from West at 16 mph with gusts up to 28 mph, scattered clouds
31% Humidity Sketches were done with black Strathmore paper and colored Conte’ crayons.

Erika Rix

Cold clouds

This large prominence was on the sun’s south west limb on March 27, ’07. Activity was otherwise low. Paradoxically, prominences are cooler than the surrounding atmosphere. They are columns of sun-stuff trapped and held up in the magnetic fields above the solar surface. The trapped plasma cools, recombines into hydrogen atoms and then emits visible light to show up as a prominence. The glowing gas twists and swirls in the sway of the magnetic fields and can change its appearance from minute to minute.

Observed from England at 10.30UT through a SolarMax60 H-alpha ‘scope at 50-80X, seeing moderately steady. The sketch was made large on A4 Canford black cartridge paper using white Derwent Studio and Derwent Watercolour pencils, the latter dry. I try to avoid erasers or blending stumps as they can sometimes take away the immediacy. If necessary, unwanted marks or brightness are reduced with lines of black Derwent Studio pencil. It is necessary to work fast and to finish a sketch within ten minutes, any longer and the scene can alter significantly. Details of this prominence were changing quickly but it was visible in more or less in the same overall form for over two days.

Les Cowley

Stop by and take a look around Les’s spendid daily website “Atmospheric Optics”. Click on the link in the blogroll.

Radiant spectacle

Today, March 2, 2007, the sunspot number is zero.

The sunspot number on October 28, 2003 was 238. An X-17 solar flare erupted that morning. Sunspot groups 484,486, and 488 were associated with Coronal Mass Ejections and auraural activity. The attached watercolor was based upon a white-light solar image captured with a 4″ refracting telescope, a white-light-solar filter, and a digital camera. The image of the sun with sunspots 484, 486, and 488 was processed in Photoshop and then printed. In a photocoping machine a transparancy was made. The transparancy was placed on an overhead projector and the projected image was traced and colored with watercolor pencils. Then, with a brush, water was added to the sunspots and to the remaining surface and background.

If the use of an “overhead projector” sounds like something from a school project, it was. Students at the A.R. Gould School in South Portland, Maine have used this process numerous times to document their observations.

… just a thought about tracing. In the late ’90s, I sent a cardboard-box camera obscura to Betty Edwards, the author of “Drawing on the Right Side of the Brain”. In her book she recommends that one should try to copy an image that is upside down; she suggests that that may allow the observer/drawer to see what is there and not what one expects to be there. In the camera obscura that I constructed, the image was projected upside down. In our conversations I asked her about the whether she thought tracing was drawing. She said that if two people were to trace the same thing that the finished drawings would be different, because drawing is about how we see things. (She also said that tracing allowed muscles to build muscle memory. I suppose that that is similar to practicing scales in music.)

John Stetson