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Quasar 3C 273


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About this observation
John Coffin
Time of observation
11/04/2019 - 00:30
3C 273
Observing location
Alpy 600 spectrometer
Atik 460 EX
Celestron 8 Edge HD with 0.7 x reducer
Lodestar Guide Camera
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The spectrum of the quasar was collected with 6 x 600 second exposures and processed in ISIS. It was exciting to be able to capture the spectrum of one of the most distant objects an amateur astronomer is ever likely to observe. The redshift is z = 0.158 when the H beta (5627 A), gamma (5026 A) and delta (4750 A) are measured and 0.156 when H alpha is measured (at 7587 A). I suspect the Alpy calibration is not accurate at 7587 A. 

I calculated the distance of this object using Ned Wright's cosmology calculator and the comoving distance is 2.13 x 10^9 light years. I discovered there are at least four different ways of measuring distance, the comoving distance tells us how far away the galaxy is now, adjusting for the expansion of spacetime and assuming a 'flat' model of the universe. Anyway, it's a long way!


Andy Wilson's picture

Hi John,

That is a great spectrum of a faint target. It is interesting to see how far equipment can be pushed and you achieved a very nice signal in your hour long integration. The broad emission lines showing up very clearly.


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