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Observation by Kevin Gurney: Redshift in quasar 3C 273

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Kevin Gurney


Kevin Gurney


2017 Mar 25 - 03:05


2017 Mar 30 - 20:46



  • Celestron 8SE
  • Alpy 600
  • Atik 630EX
  • AZ-EQ6
  • 0.63 FR

3 x 10min subs


West Sheffield

Target name

3C 273


Redshift in quasar 3C 273

About this image

3C 273 is a quasar at around 2.5GLy away with a published redshift of 0.15. Since learning to use the Alpy spectrograph I have wanted to observe the cosmological redshift of a distant object, and this quasar is a classic 'testbed' for doing this as I believe its the brightest of its type. However, it was a challenge for me because, at mag 13.0, in West Sheffield suburbia, the signal in the spectrum  was getting lost in the skyglow lines. I eventually got something useable after binning at 2x2 (trying 4x4 next time).

Comparison of the smoothed spectrum with professional data shows (I think) a reasonably good match of the main features and my estimated redshift was close to that reported there.

Files associated with this observation
Like this image
Nick Atkinson
Nick Atkinson, 2017 Apr 12 - 09:23 UTC

Well done and who would have thought this was possible with amatuer equipment

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