Sketch.
Seestar S50.
Orwell Astronomical Society (Ipswich)
Sketches Of The Sun,
04 June 2023 - 20 March 2025
This page shows sketches of the solar disk made with the following instruments:
Sketches made at the eyepiece of the PST were produced using a pencil and/or crayons. Some of the resulting images were scanned and subsequently post-processed in Gimp v2.6.
Sketches made at the eyepiece of the C4R were post-processed as follows:
Sketches made at the eyepiece of the LS35 were made as follows. Initially, the etalon was detuned to a white light view. This allowed the major sunspot groups to be sketched, providing suitable anchor points for the remainder of the image. The scope was then properly tuned by adjusting the thumbscrew by one to two turns to provide an optimal Hα view with best contrast of features including prominences, filaments and active regions. This enabled the sketch to be completed quickly.
Below left is a sketch made at the eyepiece of the LS35. I used a 20 mm Plössl eyepiece providing a magnification of 20x. The sketch has been L-R inverted to give a "true" image. The Sun appeared orange-red in colour with the surface having a texture similar to that of orange peel. The sunspot near the centre of the disk was black. Solid lines represent filaments, which appeared brownish; dotted lines represent active regions, which appeared sandy-coloured. Interesting prominences including a fan and a magnetic loop were visible on the upper-left limb.
Below right is an image captured on the same day by OASI Chairman Andy Gibbs, using a Seestar S50 in "solar" mode.
Sketch.
Seestar S50.
Below left is a sketch made at the eyepiece of the LS35. Below middle is the GONG (Global Oscillation Network Group) image from the National Solar Observatory. Below right is a photo of the Lunt LS35 on an EQ5 mount. The mount was (converted to Alt-Az by orienting the polar axis vertically. It makes the setup light and portable (and is a useful technique for larger refractors too).
Below left is a pencil sketch made using the PST with a 20 mm Plossl eyepiece providing a magnification of 20x. After some trial and error to achieve optimum focus, I found cupping my hands around the eyepiece significantly improved contrast. Wearing a wide brimmed hat reduced the glare from the Sun, and an adjustable observing chair provided a comfortable posture! My technique was detune the PST to the white light range to sketch the sunspots: this helped to anchor the sketch. I then returned the PST to the Hα range to sketch active regions, prominences, and filaments.
The colossal sunspot group AR13664 (labelled below in shortened form as 3664) triggered an intense aurora on 10 May.
For comparison purposes, below right is an image taken on the same day by the Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO).
Sketch.
HMI aboard the SDO.
Sketches of the Sun in white light using the Celestron C4R with a Star 25 mm Plossl eyepiece providing a magnification of 40x. Comparison of the images shows the motion and evolution of active regions on the solar disk.
06 December 2023.
08 December 2023.
Creation of a sketch of the Sun using the PST with a 20 mm Kellner eyepiece providing a magnification of 20x. The image features prominances, filaments and active regions. Left-right: orignal pencil sketch, scanned version with colour added, final version with marbling added to prove the most realistic representation of the view through the eyepiece.
Sketched using the PST with a Meade 26 mm Super Plossl eyepiece providing a magnification of 15.4x. The image features prominances, filaments and active regions.
Sketched using the PST with a Meade 26 mm Super Plossl eyepiece providing a magnification of 15.4x. The scanning process lost some detail but retained key features including prominances, plages, filaments and active regions. Clearly a lot was happening on the solar disk!
Neil Morley