Will the Vera Rubin telescope be able to measure Hubbles Constant universe expansion. Have any universe expansion measurements been done so far?
Dear David,
Yes, the Vera C. Rubin Observatory is expected to contribute to measuring the Hubble constant, though indirectly, by providing massive datasets of supernovae, strong gravitational lenses, graviational wave follow-up, and galaxy distributions.
For a basic description of how Rubin will contribute to measuring the expansion of the Universe, I recommend Keith Bechtol’s 15-minute video lecture, “The Expanding Universe as Seen with Vera C. Rubin Observatory,” available on the Rubin Education site here: Videos and Auxiliary Content | Rubin Observatory .
For a more detailed technical description, I recommend the LSST Science Book – particularly Chapter 11 (“Supernovae”), Chapter 14 (“Strong Lensing”), and Chapter 15 (“Large-Scale Structure and BAO”) – which is available in PDF format here: https://www.lsst.org/sites/default/files/docs/sciencebook/SB_11.pdf .
In addition, there is a relatively new method described by Rupert Croft (“Direct Geometrical Measurement of the Hubble Constant from Galaxy Parallax”) that predicts that Rubin could statistically detect this effect to provide a direct, geometric measurement of the Hubble Constant. Rupert Crofts paper can be found here: Direct geometrical measurement of the Hubble constant from galaxy parallax: predictions for the Vera C. Rubin Observatory and Nancy Grace Roman Space Telescope - ADS
As to your second question – “Have any universe expansion measurements been done so far?” – I am afraid it is still pretty early in the Rubin data taking for any firm measurements of the Hubble Constant by Rubin just yet. That said, Rubin will provide essential data in the coming years for unprecedented measures of the Hubble Constant and the overall expansion of the Universe!
I hope this helps!
Many thanks!
Best regards,
Douglas
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