Accurate distances to Galactic globular clusters through a combination
  of Gaia EDR3, HST and literature data
  We have derived accurate distances to Galactic globular clusters by combining
data from the Gaia Early Data Release 3 with distances based on Hubble Space
telescope HST data and literature based distances. We determine distances
either directly from the Gaia EDR3 parallaxes, or kinematically by combining
line-of-sight velocity dispersion profiles with Gaia EDR3 and HST based proper
motion velocity dispersion profiles. We furthermore calculate cluster distances
from fitting nearby subdwarfs, whose absolute luminosities we determine from
their Gaia EDR3 parallaxes, to globular cluster main-sequences. We finally use
HST based stellar number counts to determine distances. We find good agreement
in the average distances derived from the different methods down to a level of
about 2%. Combining all available data, we are able to derive distances to 162
Galactic globular clusters, with the distances to about 20 nearby globular
clusters determined with an accuracy of 1% or better. We finally discuss the
implications of our distances for the value of the local Hubble constant.
