Sun July 21 with Sol'Ex

National holliday in Belgium with some Sun at midday. I took time to adjust for HeD3 line in view of the coronal hole. Next, images were taken in CaIIH and CaIIK with good result. In all images the flare in AR4493 is visible... really cool.

Setting: Sol'Ex by James R on TLAPO80 and ASI678MM.
Tilt: not so good due to manipulation. May be I need to glue the connections together

Sx/Sy = 1

Software : SharpCap, Inti, DeNoise AI and CS4.

 

500.000 Visitors on my Blog. Big Thank You

Today my Blog reached 500.000 visitors. Wow half a million visitors. Thank you all for reading my blogposts.

Solex Processing HeID3 using INTI Software

While I previously relied on JSolex for spectroheliogram processing, I had not yet utilized Inti to process the neutral helium HeID3 spectral line. My motivation stems from the insights presented in Christian Buil and Valérie Desnoux’s book, Guide de l'observation solaire avec un spectrohéliographe. In particular, the potential of the HeID3 line to reveal low-contrast features such as coronal holes makes it a compelling target for high-resolution solar imaging. This post outlines a step-by-step workflow for processing HeID3 observations using Inti.

Version: Inti V7.0.3

After starting Inti, open the file and select "safe polynome coefficientt". Next run the proces by selecting Go! 

My ROI includes both the NaID2, FeI (5888,81) and HeID3 line. Inti uses the NaID2 line as reference. Christian mentiones that ROI with only FeI and HeID3 would be better.

Next, select Helium-Corona free page and mark "automatic polynome computation" and "Transversllium correction". The shift is currently not important and you can put in zero aswell. Offset 1 on -8 and Offset on 12. Run the process selecting Go!

Select Frame and Mean-Start. When doing this the shift from NaID2 to HeID3 will be calculated automatically. You can also select the line by clicking on the HeID3 line and pressing OK.  Next run the process by selecting Go!

Depending on the outcome, play around by changing the shift value by plus or minus 1 and find the most contrast image.

After editing in CS4, this is result... which also shows the coronal hole. 

Sun July 19 Sol'Ex

Imaging the Sun on July 19 using Sol'Ex on TLAPO80/480 and ASI678MM. On the eastern limb a new sunspot arises AR4492 with a nice peak prominence.

New Sol'Ex book

I finally bought the book "Guide de l'observation solaire avec un spectrohéliographe" by Christian Buil and Valerie Desnoux, subtitled "Explorer le Soleil invisible avec Sol'Ex".

There’s just one major catch... it’s written entirely in French, and there’s no sign of an English translation anywhere on the horizon. Since my French is pretty rusty, this is going to be a real challenge—but exploring the 'invisible Sun' with the Sol'Ex will be well worth the effort!

Moon and Venus with my Weatherstation

A beautiful alignment of the Moon, Venus and my weatherstation.

Heat waves 2025 and 2026 (so far)

A heat wave is an extended period of anomalously high atmospheric temperatures driven by synoptic-scale anticyclones, where sinking air warms adiabatically and suppresses cloud formation. This allows uninterrupted solar radiation to directly heat the Earth's surface, creating a thermal feedback loop amplified by dry, low-specific-heat sandy soils like those in Averbode. In Belgium, the official threshold requires at least five consecutive days reaching 25 Celsius or higher, with at least three of those days exceeding 30 degrees Celsius. The localized environmental and thermodynamic impacts of these specific atmospheric events in Averbode are outlined below with a comparison of the official data of KMI Uccle.

For Averbode we have more heat waves then official registrated by KMI in Uccle. Also the lenght of the heat waves are longer. 

Data is measured using weather station:  Levenhuk - WU ISCHER75 or EcoWitt EasyWeatherPro-16ACFC

Sun July 15 different wavelengts

The Sun in different wavelengths.

Setting: Sol'Ex by James R on TLAPO80/480 and ASI678MM

Herschel Wegde, 2nd Gen Slit and IR Cut Filter

Tilt <0,5° and Sx/Sy=1

Software: SharpCap, Inti, JSolex, DeNoise AI, CS4

Sun July 14

Very good seeing this morning. Mount was polar aligned and Sol'Ex was foreseen with an IR Cut filter.

Setting: Sol'Ex by James R, Herschel Wedge and IR Cut filter

TLAPO80/480 with ASI678MM Camera

Sx/Sy = 1 and tilt 0,2°

Software: SharpCap, Inti, JSolex, CS4, AstroSurface and DeNoise AI

 

MgIb2 (-1 pixel or 0,06A)

July 11 Prominences

Images of the Sun and it's prominences. Images are inversed.

Prominence July 12

Prominence on July 12, 2026.

Solar Observation Day

On July 5th, the Belgian astronomy association VVS organized its annual National Solar Observation Day. Our local astronomy club, Helios, was proud to take part in this nationwide event. The activities were held at Het Moment, located on the beautiful grounds of Averbode Abbey, providing a wonderful setting for a day dedicated to astronomy.

Despite the less-than-ideal weather, we were delighted to welcome around 200 visitors throughout the day. Many came hoping to observe the Sun through our specially equipped solar telescopes and to learn more about our nearest star.

Unfortunately, the weather had other plans. Thick clouds covered the sky from morning until evening, preventing us from showing the Sun to our visitors. While this was disappointing for both the public and our volunteers, the enthusiasm of those who attended never faded.

Instead, we spent the day explaining how solar observations are carried out safely, discussing the features that can normally be seen on the Sun—such as sunspots and prominences—and answering many questions about astronomy and our observing equipment. Although the Sun remained hidden behind the clouds, it was still a rewarding day filled with interesting conversations and a shared passion for astronomy.

We hope for clearer skies next year so we can give our visitors the spectacular solar views they came to see.


Written by Pascal and rewritten by AI

Amazing Prominence July 4th

 

Observation of an amazing prominence on July 4th. The image was made using my Sol'Ex on TLAPO80/480 with ASI678MM.

Editing using Inti, DeNoise AI and CS4.

Sodium, Magnesium and Calcium with Sol'Ex

Sol'Ex observation in Sodium (NaID2), Magnesium (MgIb2) and Calcium (CaIIH). The comparison shows sharp and delineated supergranulation in MgIb2 and less in NaID2 and fully scattered in CaIIH.

MIT Open course

 ince 2001, MIT OpenCourseWare (OCW) has created new opportunities for learners and educators around the world. We’re sharing Open Educational Resources (OER) from MIT and helping to lead and sustain a global revolution in free access to knowledge. Now in our 25th year, this vital mission has never been more important. MIT OpenCourseWare will continue to share the latest teaching and insights from MIT faculty, and collaborate across the dynamic open knowledge ecosystem to build a world of more vibrant, equitable and inclusive education for all.

see more this link and enjoy learning  https://ocw.mit.edu/

Near occultation of ZC797 by Helios is published in magazine Heelal

The observation by Helios (Bart, Lieven and Myself) of the near occultation of SAO77121 by the Moon is published in Magazine Heelal of July 2026.The description of this observation can be found in my blog via this link 

 https://pascalhilkensastropage.blogspot.com/2026/03/near-occultation-of-sao77121-by-moon-on.html

Supernova SN2026fvx published in magazine Heelal

My observation of Supernova SN2026fvx is published in Magazine Heelal of July 2026
See my blog: https://pascalhilkensastropage.blogspot.com/2026/04/sipernova-sn2026fvx-in-ngc4205.html

Sun Sol'Ex June 28

 

Active sun in different wavelenghts using Sol'Ex by James R on TLAPO80/480 and ASI678MM.

Noctilucent Clouds June 29

Finally, I could capture noctilucent clouds. The last time I could observe them was back in 2024.

Noctilucent Clouds (NLC) June 28

Some NLC "behind" low clouds.

Filament 109km/s AR4478 Solex

Filament eruption near AR4478 on June 25. I repaired my Sol'Ex by James R and I completed a try out together wtih Lieven, a Helios colleague.

After taking the first scan, a filemant showed up in Ha2cb. Using JSolex, the speed is abt 109km/s

A made a couple of gif images to show the dynamics across different wavelengths; from 0,5 till 2,5A and -0,5 till -2,5A from the centre of the H-Alpha line.

Setting

- Sol'Ex by James R, 2nd Gen Slit, TLAPO80/480 and ASI678MM

- Herschel Wedge

- tilt -2,6° and Sx/Sy=1

- Software : SharpCap, Inti, CS4, JSolex