Difference: LogBookAstronomyEntry0149 ( vs. 1)

Revision 125 Oct 2017 - LenaLenz1

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META TOPICPARENT name="LogBookAstronomy"

Log Book Entry No.149

Days, Calendar Created: 25 Oct 2017 13:14:14 Days, Calendar Last Revised: 25 Oct 2017 13:14:14 Person LenaLenz1 Text Solar Limb Darkening Taking Data AC LL

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10:30 dome. Bedingham, Cozens, Lenz

  • good weather => took a few images with Canon SLR camera
  • The following settings received best results: ISO=100, exposure time=1/4s to 1/8s, max. f-number
  • Used rawkit Python package to transform .cr2 files into .tiff
  • Applied Hough transformation to find circles in image
  • Measured brick width L with ruler and received distance D from dome to boiler house brick via Google Maps
    => L = 22cm, D=104m
  • From this calculated angle to be θ = 2*arctan((L/2)/D) = 0.117 = 0.22x(angular separation of sun(0.5))
  • Next steps: - take image of smooth white background to measure the vignetting effect of camera
    - adjust parameters of Hough transformation to find correct circle

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META FORM name="%25SYSTEMWEB%25.LogBookForm"
FORM FIELD Subject Subject Solar Limb Darkening Taking Data AC LL
FORM FIELD Status Status blank
FORM FIELD Author Author LenaLenz
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