Sun in CaIIH1v using Sol'Ex by James R

 

All details see blogpost https://pascalhilkensastropage.blogspot.com/2025/07/first-light-of-solex-by-james-r.html

First Light of Sol'Ex by James R

I decided to go for the Sol'Ex design by James R as my previous two versions of my Sol'Ex (version 1 and pro version) are difficult to adjust concerning the collimator. I learned from Christian Buil that switching between H-alpha and CaIIH/K requires adjusting the collimator. I found this out but it was difficult to do this with version 1 and pro version of the Sol'Ex. The mechanism by James R is promising and looks easier to adjust the collimator.

My Helios colleague Johan L completed all the 3D print work which resulted in a very nice Sol'Ex: matt black, strong and robust design. The optics were bought from Shelyaq instruments which currently includes the 2nd Gen slit of 7micron width and 6mm height.  The ZWO camera requires no extra tube as needed for the pro version.

First light: TLAPO60/360 with ND 16 filter was used with new Sol'Ex by James R. After fine tuning the focus of the mount and camera, I started to adjust the collimator. After some back and forth I was able the make my first scan using the H-alpha line. Inti was used to see the result and this was already very good. Next was the CaIIH line. Adjustment is very easy but finding the sweet spot is of course the challenge. Even though the seeing was moderate the Inti result of the CaIIH line was quit good. 

SharpCap Log for H-alpha line:

Output Format=SER file (*.ser)
Binning=1
Capture Area=3840x100
Colour Space=MONO16
Exposure/Gain Shift=0
Temperature=34,2
Hardware Binning=Off
High Speed Mode=On
Turbo USB=100
Flip=None
Frame Rate Limit=Maximum
Gain=144
Exposure=3,4720ms

SharpCap Log for CaII line:

Capture Area=3840x124
Colour Space=MONO16
Exposure/Gain Shift=0
Temperature=34,3
Hardware Binning=Off
High Speed Mode=On
Turbo USB=100
Flip=None
Frame Rate Limit=Maximum
Gain=166
Exposure=5,4330ms

So far I'm happy with this new version of the Sol'Ex with the design by James R.

E corona through Fe XIV - Description Setting

Imaging the E-Corona (Emission corona) through the Fe XIV line which millions time fainter then the photosphere. 

 

JSolex 3.3.2 ImageMath E Corona Script

Improved setting by Olivier Aguerre
# Reference (darkest line) of the scan (in Å)
refWl=5302.29
# Corona-E line (in Å)
targetWl=5302.90
# Continuum shift 1 (in Å)
c1=5301.5
# Continuum shift 2 (in Å)
c2=5303.6
# Fe XIV FWHM (in Å)
targetWl_fwhm=0.2

Original setting by Cedric Champeau

# Reference (darkest line) of the scan (in Å)

feI=5302.29

# Corona-E line (in Å)

feXIV=5302.86

# Continuum shift 1 (in Å)

c1=5301.84

# Continuum shift 2 (in Å)

c2=5303.44

# Fe XIV FWHM (in Å)

feXIV_fwhm=0.2

I made also 66 scans using my Sol'eX Pro 2nd Gen slit. JSolex 3.3.2 is used to stack the images. Editing was done using CS4, AstroSurface and DeNoise AI.

Use of baader continuum 8nm filter 540nm which is tilted and installed in front of the slit; getting 530nm.  
Binning 2x2 and 14ms, Gain 0. Sun at 18° above horizon and transparency not 100%.

E-Corona Fe XIV Rework using JSolex 3.3.2

A new imagemath script was available July 18. I uploaded the new script into JSolex 3.3.2 using this link (https://github.com/melix/astro4j/tree/main/jsolex/src/main/resources/me/champeau/a4j/jsolex/templates)

A new batch of 66 scans werd uploaded and processed. Editing using CS4 and DeNoise AI gives following result.

Compare this with image of 45 scans on July 16 from Cédric Champeau

Sun in FeI 5302,3A

 

Imaging the Sun in FeI 5303,3A with Solex Pro, 2nd Gen slit and ASI678MM.
Sunspots are visible aswell as some structure but I'm careful as setting is bin2x2 and scanspeed was 32x sidereal.

E Corona FeXIV Third trial

 

Good news, I can tilt the baader continuum filter (540nm) towards 530nm. The light cone is now central around the Fe XIV line. 

I made also 66 scans using my Sol'eX Pro 2nd Gen slit. JSolex 3.3.1 is used to stack the images. Editing was done using CS4, AstroSurface and DeNoise AI. 

Binning 2x2 and 14ms, Gain 0.

Some more details are visible but still wat I would expect. Transparency was not 100% and the Sun was about 18° above the horizon. Something to keep in mind next trial. 

Anyhow...cool this E-Corona. 

E-Corona Fe XIV Second Trial

This is my second trial to image the E-corona using Fe XIV.

Some background information:

- use of 8nm double stacked baader continuum filter

- continuum filter was tilted but probably should be more inclined as the cone was not central over FeXIV line

- could not find the spectrum when using TLAPO80/480 with herschel wedge

- change to TLAPO60/360 with ND16 filter

- use of 2 micron pixel 678MM camera

- setting

    - sol'ex pro 2nd gen slit

    - exposure time 11ms, gain 12 and 32x sidereal speed

    - total of 23 images - all same direction

    - ROI of 100 pixels 

Editing using JSolex 3.3.1 with E Corona script (slightly adjusted)

Discussion and learnings:

To adjust the inclination of the continuum filter to have the cone central on Fe XIV. Saturate more the image; according to Christian Buil, increase exposure time to 100ms.

Jsolex is helpfull for the E-corona; but I hope I see some evidence of it. Currently no real structure.