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This question relates formalising the gravitational constant, $G$, (which in S.I. units is usually quoted as $\sim6.67\times10^{-11}\,\mathrm{m}^{3}\,\mathrm{kg}^{-1}\,\mathrm{s}^{-2}$) in units which are more appropriate to astrophysics, such as in the field of galaxy dynamics.

What would $G$ be in more appropriate units to astrophysics?

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Useful formulations which have taken some time to dig out:

$G\sim{4.3\times{10^{-6}}}\,\mathrm{kpc}\,\mathrm{M}_{\odot}^{-1}\,\mathrm{km}^{2}\,\mathrm{s}^{-2}$

or

$G\sim{4.3\times{10^{-3}}}\,\mathrm{pc}\,\mathrm{M}_{\odot}^{-1}\,\mathrm{km}^{2}\,\mathrm{s}^{-2}$

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  • $\begingroup$ Typo corrected, should have read pc not kpc. Thank you for the spot. $\endgroup$ – MichaelJRoberts Nov 1 '15 at 18:54

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