JSol'Ex 1.8.1. reworked HeI(D3) solar picture

JSol'Ex 1.8.1. was released and I took the opportunity to rework my solar HeI(D3) image. Using the Mathscript I made following script :

Helium_foto=img(-171)-max(range(-145;-135))

Helium_band=fix_banding(Helium_foto,25;8)

Helium_zonderbackground=autocrop(remove_bg(Helium_band))

[outputs]

Helium_Clahe=adjust_contrast(CLAHE(Helium_zonderbackground, 1);0;200)

Helium_Decon=linear_stretch(rl_decon(Helium_Clahe;10.5;4.5;10))

Helium_gekleurd=colorize(Helium_Decon; "Helium (D3)")

I got feedback from Cedric Champeau to remove the background script remove_bg

Below is my result, which is much better then my previous (see link) processing. 

Link to JSol'Ex 1.8.1. download

Link to further Java instructions

Link to Youtube instructions

Hydrogen Epsilon and Helium D3 line

I'm very proud about finding the Hydrogen Epsilon line (397,0 nm) near CaII H line and HeI D3 line (587.572nm) near Sodium D1 and D2. The lines were found using JSolex and boosting contrast which made the prominences of the lines visible.

Spectrum are captured using TLAPO60/360 with ASI290MM and Sol'Ex. 

JSolex Software

 

My earlier recordings of October 14, 2023 are reworked using JSolex software. See this link.

After downloading the exe file will start immediately. Opening the ser files and "full" run the program. the resuls are comparable with Inti and SHG_Main. The colorcoding is a nice option. The protus of Inti and SHG-Main perform better. Overal this software can compete with Inti.

Image : TSAPO60/360 ASI290MM with Sol'Ex, CaH line.

Comparison between First Solar Picture by Fizeau and Foucault and mine 179 years later

F. Arago, Popular Astronomy, Volume 2, Book XIV, Chapter XXVII, p176 (1855)

The first successful photograph of the Sun was taken by the French physicists Louis Fizeau and Léon Foucault on April 2, 1845.For this, the solar light was reflected horizontally by a heliostat to a lens, at the focus of which a daguerreotype was placed. But the Sun is so bright that the exposure time was to be between 1/60 and 1/100 of a second: it was not possible to use the usual method of a cover removed and replaced manually on the lens. Fizeau and Foucault imagined an “original enough” shutter consisting of a plate with a horizontal slit of appropriate width, which they dropped in front of the camera: this was the ancestor of the curtain shutter. The picture showed sunspots aswell as limb darkening. The limb darkening was subject of debate those days. 

Compare with my recent picture of the Sun, 179 years later :)

References: 

- F. Arago, Popular Astronomy, Volume 2, Book XIV, Chapter XXVII, p176 (1855)

- NASA : Technology through time Issue sheet #40, First Sun Photo

Imaging Sun in Helium (D3) line

My Helios collegue, Walter, informed me about a new imaging software SHG_Main for spectroheliographic images of the Sun. My files from October 14, 2023, which included Sodium D1, D2 and Helium (D3) could not be processed using INTI software. So after installing SHG_Main I succesfully processed the data and after editing I got a solardisk in Helium D3. My first one even!

The software has a "spectrum" tab which searches for different lines. In my case I anchored Na (D1) and Na (D2) and after calculation of the dispersion factor the software found the He D3 line (see graph).

An Helium D3 image was made using the data from the spectrum tab and another image was made with -10 pixels further away from He D3 line. Both pictures were substracted from each other using CS4 and false colours were added. 

I do remember that the data set was made under windy conditions which prevented a smooth recording that day. 

Comparison between solar pictures in H-Alpha, CaK and He D3. All pictures taken on October 14,2023. All three pictures show prominences. 

Moon halo, Moondogs and paraselene circle

This evening the moon was surrounded by a 22° Halo, Moondogs east and west of the moon and paraselene circle (not parahelic circle as this is for the Sun).

Setting : Nikon D7500 15mm f/4 ISO1600 2,5s

Setting : Nikon D7500 10mm f/3.8 ISO1250 4s

Editing : CS4

Sun CaK What to see

 

What to see when we image the Sun in Ca K line?

- Plages or Chromospheric Faculae : Most of us are familiar with photospheric faculae which can normally only be observed towards the edge of the solar disc in white light when it is possible to view a higher region in the photosphere. These bright mottles can be up to 50,000km long and are caused by underlying magnetic fields. They are often a good predictor of future active region development and can also remain long after an active region has dissipated. The average lifetime of faculae is about 90 days and they are around several hundred degrees Kelvin hotter than the surroundings (therefore appear bright).Chromospheric faculae can be observed anywhere on the solar disc and they are an extension of the photospheric faculae into the chromosphere, details of this link are still not fully understood. Areas of very dense magnetically bright faculae or plage occur in active regions and are a good predictor of the occurrence of future sunspot formation (Evre, S. 1999). Polar faculae are short lived and only observed just before and around the solar minimum.

- Supergranulation Cells- Chromospheric Network Structure: in the quiet sun most of the chromosphere seen in Ca II K appears like a bright network pattern of irregularly shaped circles. The size of these cells is around 30,000-35,000 km in size and their average lifespan is around 20 hours. (Bhatnager, A. 2005). This is a pattern of weaker magnetic fields (the quiet network) where the magnetic elements are mixed in polarity. These are also called the intranetwork fields and the brighter edges can also be called faculae. The supergranulation cells are large scale convective horizontal flow, where material flows outwards from the centre and downward flow has been observed at the boundaries. The flow carries both polarities to the boundaries (Zirin H. 1988 p126).

- Bright rings around sunspots

- Sunspots

- K-Grains or bright points: K grains are 'intranetwork bright points' found in the quiet sun. Intranetwork bright points, cell flashes or cell grains, originate exclusively within cell interiors in quiet areas of the solar surface. These are observed almost exclusively in the Calcium H (396.85nm) and K lines (Rutten et al. 1991). They are intermittent localised brightenings which last less than a minute and often re-appear a few times at 2-4 min intervals at about the same place, and frequently occur in pairs. In Figure 2, the labelled brightenings are an example only. These bright points are tiny and good resolution is needed to observe these features. To identify them definitively, a time lapse study would need to be embarked upon and the brightenings studied to assess whether they follow the pattern of re-emergence and disappearance, again another good area for amateur study. It has been observed that these K grains do seem to correspond with G-band brightpoints observed in the intergranular lanes in the photosphere (Lite et al. 1998).

- Filaments

- Prominences

Source: https://solarnutcase.livejournal.com/1047.html