A discussion at our last astronomy club meeting had me thinking it would be fun to try sketching the Sun over a period of time. As luck would have it, I had made a sketch earlier that afternoon, so decided to give it a go for a week.
All observations were made using the TMB 80 refractor and a Delos 10mm eyepiece @ 48x. I did try using the R.C but found the TMB’s image was just that little bit sharper, no matter what eyepiece combo I used on the bigger scope. The detail sketch made on the 24th was made using the Altair Astro 250mm with Delos 14mm @ 145x
The one thing that did surprise me is how well the positioning matches the SOHO images taken on the same day. I didn’t use any kind of grid on the eyepiece or the drawing to help locate positions, which just goes to show how well the eye is capable of judging such things.
One problem I did find was with the scope mounted on an Alt Az mount. The cardinal points rotate in the FOV over the course of a day, which make aligning all the images so North was upward, proved to be a real pain. This changing angle is called the parallactic angle. Fortunately I discovered Helio Viewer suite of software by Peter Meadows which helps with this alignment. The software will also calculate the sunspot latitude and longitude as well as many other measurments. I’ve downloaded the software and once I understand how these all work, will try running my sketches and images through them.
I’ve also dug up a copy of the BAA’s ‘Observing Guide to the Sun’ that I aquired at the Winchester Weekend this year – which I guess I ought to read 🙂
21, June 14:04 UT. Seeing: II: Mostly Stable Transparency: V: Poor
22, June 15:56 UT. Seeing: II: Mostly Stable Transparency: IV: Somewhat Clear
23, June 16:33UT. Seeing: IV: Unstable Transparency: V: Poor
24, June15:18. Seeing: IV: Unstable Transparency: II: Clear
24, June 15:49UT. Close-up detail of Sunspots 2095 and 2097.
25, June 17:07UT. Seeing: IV: Unstable Transparency: V: Poor
26, June 16:23UT. Seeing: IV: Unstable Transparency: IV: Somewhat Clear
27, June 17:33UT. Seeing: IV: Unstable Transparency: V: Poor
Search
Categories
Archive
- July 2020 (2)
- April 2020 (2)
- March 2020 (3)
- February 2020 (2)
- November 2019 (1)
- May 2019 (2)
- April 2019 (3)
- February 2019 (2)
- January 2019 (4)
- November 2018 (2)
- October 2018 (1)
- September 2018 (1)
- May 2018 (1)
- April 2018 (3)
- March 2018 (2)
- February 2018 (5)
- January 2018 (4)
- October 2017 (3)
- September 2017 (7)
- August 2017 (14)
- July 2017 (19)
- June 2017 (19)
- May 2017 (28)
- April 2017 (26)
- March 2017 (35)
- February 2017 (43)
- January 2017 (8)
- December 2016 (3)
- January 2016 (3)
- December 2015 (1)
- November 2015 (2)
- October 2015 (4)
- September 2015 (8)
- August 2015 (2)
- May 2015 (1)
- April 2015 (3)
- February 2015 (1)
- January 2015 (1)
- December 2014 (3)
- November 2014 (2)
- September 2014 (3)
- August 2014 (1)
- July 2014 (4)
- June 2014 (4)
- May 2014 (4)
- April 2014 (2)
- March 2014 (1)
- January 2014 (1)
- December 2013 (2)
- November 2013 (2)
- September 2013 (2)
- August 2013 (3)
- July 2013 (3)
- June 2013 (1)
- May 2013 (4)
- April 2013 (6)
- March 2013 (2)
- February 2013 (6)
- January 2013 (2)
- December 2012 (1)
- November 2012 (1)
- September 2012 (5)
- August 2012 (4)
- July 2012 (2)
- June 2012 (5)
- May 2012 (12)
- April 2012 (1)
- March 2012 (2)
- June 2011 (1)
- May 2011 (2)
- March 2011 (3)
- February 2011 (3)