Sunspot AR4392 March 22

 

Inverted image of H-alpha spectrum of the Sun from last Sunday March 22, 2026. Crop from AR4392.

Picture made using SolEx with ASI678MM on TLAPO80/480.

Halo 360°

Capturing a very bright 360° Halo around the Sun.

Coronal Hole and Sol'Ex images March 22

My Sol'Ex was used to capture the HeD3 line and after editing is was possible to bring forward the current coronal hole of the Sun. A comparison was made with SDO/AIA 211A and GOES19 195A. All in all it's not most beautiful picture but still I could capture the coronal hole. For sure I will try this again when a more deligned coronal hole shows up.

The day started with some bad seeing but during noon time seeing became better. I made time to adjust the Sol'Ex and was able to get sharp images in all captured wavelenghts.
Tilt was corrected with some very good results: 0,1° deviation... not bad at all. The most suffer from dust on the slit. Yesterday I did some cleaning, but not enough it seems. 

Sun March 21

The Sun this afternoon, observed with Sol'Ex in H-alpha and CaIIH.

CaIIH1v

Sun in CaIIH

My last So'Ex observation was on January 4th this year. So today it was some trial and error...

Sun today in CaIIH 

Sol'Ex by James R with TS TLAPO80/480 and ASI678MM

SharpCap, Inti, CS4, DeNoise AI

Space Weather and Avidos - VVS Sun Working Group

Last week, March 8th, I attended the Sun working group of the VVS. Beside giving a lecture on "how to observe the E-Corona using a Sol'Ex" an interesting lecture was provided by Jan Janssens of the SIDC (Royal Observatorium of Belgium) of space weather and the aurora of Jan 19, 2026.

Selfie with Jan Janssens of SIDC 

In his lecture he refers to radiation during spaceflights and shows a link to the website. I searched this website and it's an ESA website in Sweden. After registration I could simulate my exposure during my flight from Brussels/Beijing in Jan last month. This was about 30microSv. 

Normal natural exposure in Belgium is about 2,4mSv. When going through the details, CT en PET scans are responsible for 7mSv for CT and 4,5mSv for PET. I wasn't aware this was such high.

This is the link to Avidos

This is the link to the dashboard 

ATT-Essen - 50 days to go

50 days to go ... May 9th is the day for the ATT Essen, the ATT (Astronomie- und Techniktreff) is the biggest trade fair for amateur astronomers.

For more information see this link.