Spectroscopy Basics

Faint Objects

  • Capture at least 5x15mins, ideally 20 mins, max gain
  • Stack in nebulosity and save as FITS
  • Debayer (RGGB, VNG) in pixinsight then, rotate, crop
  • denoise – channel extract L, use as inverted mask, run atrous 4-5 times, save as 16-bit TIFF
  • Process in RSpec
    • Load, subtract background
    • Calibrate – 5.83A/pix on the H183c+RC8
    • Crop <4000 and > 7000
    • Instr Adjust.
  • To create instrument response curve for the current night:
    • image A or F class star at in the same part of the sky as your target.
    • Load star spec into Rspec and calibrate using well-known lines.
    • Load smoothed ref spec of correct class as Reference.
    • Delete <4000 and >7000, divide main by ref.
    • Move back to main, then smooth and save Ref as Inst Resp curve for today along with your spectra.
  • To create smoothed ref spec
    • Load reference spectrum into RSpec, crop <4000 and > 7000
    • delete absorbtion lines, fit spline through data
    • save ref as SmoothedA3V or whatever in the UserData directory.