Contains:  Solar system body or event

160 minutes of Jupiter's rotation and the Great Red Spot

160 minutes of Jupiter's rotation and the Great Red Spot

Equipment

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Acquisition details

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Description

Here is 160 minutes of Jupiter's rotation as the Great Red Spot emerges. Look closely to see the differential rotational speeds of the gas bands. 

For this image, I captured (via FireCapture) 90 seconds of 480p video (5 ms exposure, gain 325, minimum 10k frames per capture) once every 5 minutes from 2:55 am (just before the Great Red Spot just entered view) to 5:30 am. All using an 8" EdgeHD and a Televue PowerMate 2.5x, at an effective focal length around 4350 mm (last time I estimated).  

Focus was a little better than last time I attempted this (enough to see some details in the gas band and to faintly notice the GRS in live views), and so I worked to ease off on sharpening to get more nuanced detail. For each frame, I processed: 

Autostakkert! 3
  1. Image stabilization: planet with dynamic background
  2. Stack best 50%, AP size = 24
  3. Double stack reference, RGB align, sharpened (blend RAW for 50%)
  4. 3x drizzle

Registax
  1. RGB auto balance (1024 processing box centered around Jupiter)
  2. (linear, no linked wavelets) Wavelet sharpen on the "conv" output from Autostakkert
    • Layer 1: Denoise 1.0, Sharpen 0.45, at 100
    • Layer 2: Denoise 1.0, Sharpen 0.45, at 100
    • Layer 3: Denoise 0.0, Sharpen 0.45, at 100
    • Layer 4: Denoise 0.0, Sharpen 0.45, at 100
    • Layer 5: Denoise 0.0, Sharpen 0.45, at 100
    • Layer 6: Denoise 0.0, Sharpen 0.45, at 100

Photoshop 
  1. Levels from 0 to 229, gamma 0.95
  2. Curves: linear contrast
  3. Vibrance and Saturation at 20
  4. Topaz denoise using the Low Light (default settings)
  5. Unsharp mask 150%, radius 2.5 pixels.



Estimated effective focal length: 
  • Jupiter's diameter on Sep 3: 44.26"
  • Jupiter's diameter on raw image: 320 px
  • Camera pixel pitch: 2.9 micron
  • Jupiter's diameter on raw image: 928 micron = 0.928 mm
  • Equation: focal length = (206265 * image_length_mm ) / object_angular_size_arcsec
  • So, (206265 * 0.928) / 44.26 ~ 4325 mm

Comments

Revisions

  • Final
    160 minutes of Jupiter's rotation and the Great Red Spot, Paul Macklin
    Original
  • 160 minutes of Jupiter's rotation and the Great Red Spot, Paul Macklin
    B
  • 160 minutes of Jupiter's rotation and the Great Red Spot, Paul Macklin
    C
  • 160 minutes of Jupiter's rotation and the Great Red Spot, Paul Macklin
    D

B

Title: Still frame - best capture of the GRS

Description: This still frame is probably my night's best capture of the GRS

Uploaded: ...

C

Title: Jupiter and Io at 4:03 am, just before it disappeared in Jupiter's shadow

Uploaded: ...

D

Title: Jupiter and Europa in a wider field of view

Description: And here's Europa at about 4:50 am, just barely showing as it orbits away from even this wider field of view.

Uploaded: ...

Histogram

160 minutes of Jupiter's rotation and the Great Red Spot, Paul Macklin