Click on the image to see the sequence of my prom drawings that created the animated gif. See all the movement at the end of this page
Astronomical Sketching
Astronomical sketching is not just about drawing pictures. It is about learning. This kind of sketching is about observing the subject very closely at the far end of your telescope. Sketching at the eyepiece is challenging but rewarding. However, solar sketching in hydrogen-alpha (h-alpha) is, for me, the ultimate challenge. As I have mentioned in another post on sketching, a person does not have to be good at drawing to produce a sketch or learn about a target. A person’s first efforts will not be very accurate, whether the target is an apple or the sun. Some increment of wisdom will come with every endeavour. Improvement comes with effort, trial and error over time.
Solar Dynamics
Unlike astrophotography, the sketcher processes the subject’s dynamics in his or her head, not in software. However, the brain may be the hardware of sorts if one considers all it does for us. The sketcher seizes the moment or the hours on the spot. The sun is so complex, an ever-changing vista of vigorous motion, the action of which appears to be still. In my 40mm Personal Solar Telescope (PST) using an 8mm eyepiece, the sun seems to almost fill my field of view. A tiny sphere with massive and powerful action playing out before my eye. Miniscule filaments belie their size as thousands of miles of plasma behave like ropes twisting wildly in an unimaginable stellar environment.
My first adventures with the sun involved drawing prominences on the solar limb. These eruptions’ movements are not immediately visible because of the 93 million miles between my pupil and our star. The 8mm eyepiece gives me the best view of the prominences’ details and allows me to sketch accurately. This eyepiece, coupled with continuing a delicate balancing act between focusing and tuning, enables me to see the shapes the gasses make as they move. It allows me to observe their anchor points and sometimes their disconnecting events as they leave the sun.
Focus
Because the seeing conditions can change very often during an observation, it is essential to adjust the focus regularly. Tuning also needs altering during the sessions to keep the action sharp and see the best image possible. With a h- alpha telescope, one can see some detail on and around sunspots, the umbra’s, penumbra and the shape of the spots themselves. Active regions are very detailed; fibrils, plage, and flares combine with the dark sunspots to make these areas a challenge to capture. Prominences on the limb and filaments against the disc can lure your eye into a task that can be forever daunting. So that is most likely why I began my solar sketching with just prominences off the limb, as it seemed to be the easier choice than trying to capture the entire commotion on the disc.
I remember being both amused and delighted when I found out that particularly shaped prominences have specific names such as broccoli proms and hedgerow proms. Prominences can also look like trees with many branches. They can present as complex loops within loops as the electrified plasma follows and reveals the invisible magnetic field lines present but hidden to our eyes.
Sequence
It is necessary to draw a sequence of sketches over several hours to show movement over time in proms on the solar limb. As you can see in the drawings above, there is a sequence of sketches between 10:50 UT and 19:50 UT May 15th 2008. Conte sticks on black card give the best edge for drawing these. However, I have also used ink on white paper with a fine brush from time to time. This sequence was animated via Photoshop by a friend using my still photographs of the proms. You can see the dances over time moving and swaying like trees in a storm. Another method to produce a relatively fluid sequence set is to use one of the many free gif makers online. iMovie on a Mac can also create mini-films if you use a tight transition.
This blog was first published in July 2016- updated here a little
Animated Gif of all Deirdre’s the prom sketches above. Gif made in Photoshop by Sally Russell
