Sunday, November 26, 2023

Cardinal Librarian de Zelada @ Vatican Museum - Time the Sun takes to pass across the Sundial

Pair of shutters in Vatican Museum (Pascal Hilkens)

This pair of painted shutters pertaining to the original windows of the "Sundial Gabinet" show a list of days, months,sun diameter and the time the sun takes to pass across the sundial in seconds and minutes.

This of course took my interest and I started to make my own calculations in order to compare with the data on the shutters. The easiest formula I found :


Time (seconds)  to pass across the meridan line = 128 / cos(delta)
    delta = declination of the sun at a specific day = cos ((360/365)*(N+10))*-23.7333
    N = day of the year starting at january 1

The results of both my calculation as of the shutters are shown in the graph below and are quit comparable.



The below marble sundial with bronze inlays was originally embedded in the pavement of the Vatican "Sundial Gabinet" which was the apartment of Cardinal Librarian Francesco Saverio de Zelada (1717-1801) who live here from 1780 till 1798. Only this piece did survive.

Marble Sundial Vatican Museum (Pascal Hilkens)



Cardinal de Zelada by Anton Raphael Mengs (source wikipedia)




Friday, November 24, 2023

My name with Europa Clipper to Jupiter's Icy moon Europa


My name will fly on the Europa Clipper spacecraft as it travels 2.89 billion km on its voyage to Jupiter’s exploring the Icy moon.




Sunday, November 19, 2023

Sun H-alpha Sol'Ex

Image of the Sun in H-alpha using my Sol'Ex. Conditions were not good due to clouds, wind and some issues with stability. My tilt was very good with a value of 0.5°

Setting: TLAPO860/360 with ASI290MM and Sol'Ex
Area : 1936x276; Gain 118; 4.07ms;mono16; binning 1x1
Hoya 16
Actual fps = 244
Software : SharpCap 4, SHG-Main, CS4




Tuesday, November 14, 2023

Jupiter

 

Jupiter 10days after opposition. Conditions were good which resulted in fine details.

Setting
TAL200K @f/22 with ASI224MC
ADC and IR/UV blocker
14,5ms - 3000frames
SharpCap4, AstroSurface U4 (Best 300), CS4



Jupiter 10 days after opposition

I didn't got the chance to capture Jupiter during opposition. So, this picture is made 10 days after opposition. Some wind made it difficult to capture the images.

Setting
TAL200K @f/22 with ASI224MC
ADC and IR/UV blocker
14,5ms - 3000frames 
SharpCap4, AstroSurface U4 (Best 300), CS4


Sunday, November 12, 2023

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. 





Saturday, November 11, 2023

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.