Strengthening the Open Cluster Distance Scale via VVV Photometry
  Approximately 14% of known Galactic open clusters possess absolute errors 20%
as evaluated from n>3 independent distance estimates, and the statistics for
age estimates are markedly worse. That impedes such diverse efforts as
calibrating standard candles and constraining masses for substellar companions.
New data from the VVV survey may be employed to establish precise cluster
distances with comparatively reduced uncertainties (<10%). This is illustrated
by deriving parameters for Pismis 19 and NGC 4349, two pertinent open clusters
which hitherto feature sizable uncertainties (60%). Fundamental parameters
determined for Pismis 19 from new VVV JHKs photometry are d=2.40+-0.15 kpc,
<E(J-H)>=0.34+-0.04, and log(t)=9.05+-0.10, whereas for NGC 4349 the analysis
yielded d=1.63+-0.13 kpc, E(J-H)=0.09+-0.02, log(t)=8.55+-0.10. The results
exhibit a significant (>5x) reduction in uncertainties, and indicate that: i)
existing parameters for the substellar object NGC 4349 127b require revision,
in part because the new cluster parameters imply that the host is 20%
less-massive (M*/Ms~3.1); ii) R Cru is not a member of NGC 4349 and should be
excluded from period-Wesenheit calibrations that anchor the distance scale;
iii) and results for Pismis 19 underscore the advantages gleaned from employing
deep VVV JHKs data to examine obscured (Av~4) and differentially reddened
intermediate-age clusters.
