Sol'Ex Pro-AM 2024 Results (SOLAP Project)

SOLAP Project Abstract : Systematic observations of the chromosphere and the photosphere started in Meudon Observatory 115 years ago with Deslandres spectroheliograph. An exceptional collection of more than 100 000 monochromatic images in CaII K and Hα spanning more than 10 solar cycles is proposed to the international community by the BASS2000 solar database. We started in 2023 a “PRO-AM” collaboration between professional and amateur astronomers with the Solar Explorer (SOLEX), a compact and high quality spectroheliograph designed by Christian Buil, in order to record images every day, and several times per day, owing to tens of observing stations in various places. 

I joined the PRO-AM community last summer (August '24) and submitted serveral images. All of them are visible in the BASS2000 database. https://bass2000.obspm.fr/home.php

The contribution of the amateur community compared with the professional Meudon group is plotted in below table (anno 2024)

Sun Halo

 

Sun this afternoon with a faint Sun Dog, Circumzenithal arc and Sun Pillar.

Moon-Venus Conjunction

My first observation of 2025 with a nice Moon-Venus conjuction.

Setting :

Nikon D7500 with 18-200mm lens set on 90mm

Bracketing and HDR combining using CS4. Final editing with DeNoise AI.

Happy New Year 2025

Happy Astronomical New Year 2025 with many many clear skies.

 

Comet 12P/Pons-Brooks in Big Bend (Texas)

My Helios colleague Lieven asked my why comet 12P/Pons-Brooks wasn't selected in my 2024 Highlights. My answer was that I don't have good pictures of the Comet. But then I realised that I tried to image the Comet when I was in Big Bend (Texas) a couple of days after the Solar Eclipse of April 8th, 2024. With the support from Stellarium I good trace the Comet on my images, including Uranus.

Reworked Milky Way Big Bend

I reworked my images of the Milky Way taken in National Park and Dark Park "Big Bend" in Texas (US). This is a real Bortle 1 location. 

Setting: Nikon D7500 on Sky Adventurer 2i

Lights : 44x60s

Editing: APP Stacking and Mosaic on Stars; APP Stacking and Mosaic no Stars, Light Pollution filter, Combining using CS4

Installation of new 7micron slit in Sol'Ex

I installed a new slit (second generation) in my Sol'Ex Pro version. This slit has two positions, 7 and 10micron.The 7 micron position was used. The slit support was 3D printed by a Johan (Helios colleague) and all fit well. Some advantages using the new 7 micron slit results in increasing

• the resolving power R of the SOl'Ex from 36.000 to 46.000, an increase of 27%  (using ZWO678MM camera)
• the spectral resolution from 0,18 to 0,14 angstrom for H-alpha; an increase of 22%

The "height" of the slit is now 6mm (before 4,5mm) which makes it possible to image the Sundisk using both my TLAPO80/480 f/6 with ZWO678MM camera.

All information of the second generation slit can be found in the following document from Christian Buil (https://buil.astrosurf.com/starex/slit_solex_gen2.pdf)

See specifications of the 7 micron slit: https://www.shelyak.com/produit/fente-solex-sunscan-2-positions/