New Open Clusters Found by Manual Mining of Data in Gaia DR2. (arXiv:2009.04751v2 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Casado_J/0/1/0/all/0/1">Juan Casado</a>
The physical nature of a series of 20 new open clusters is confirmed
employing existing data on putative star members, mainly from second Gaia Data
Release (DR2). The clusters were discovered as overdensities of stars by visual
inspection of either photographic DSS plates or proper motion plots of random
source fields. The reported objects are not present in the most comprehensive
or recent catalogs of stellar clusters and associations. For all of them,
clumps of comoving stars are revealed in the proper motion space. The
parallaxes of the clumped stars are compatible with the real existence of open
clusters over narrow ranges of distances. Surface density calculations, free of
most noise from non-member sources, allow in some cases differentiating a
cluster core and an extended cluster corona. Color-magnitude diagrams generally
show a definite main sequence that allows the confirmation of the physical
existence of the clusters and some of their characteristics. Two of the new
clusters seem to form a double system with a common origin. Several of the new
clusters challenge the claim of near completeness of the known OC population in
the distance range from 1.0 to 1.8 kpc of the Sun (Kharchenko et al. 2013).
The physical nature of a series of 20 new open clusters is confirmed
employing existing data on putative star members, mainly from second Gaia Data
Release (DR2). The clusters were discovered as overdensities of stars by visual
inspection of either photographic DSS plates or proper motion plots of random
source fields. The reported objects are not present in the most comprehensive
or recent catalogs of stellar clusters and associations. For all of them,
clumps of comoving stars are revealed in the proper motion space. The
parallaxes of the clumped stars are compatible with the real existence of open
clusters over narrow ranges of distances. Surface density calculations, free of
most noise from non-member sources, allow in some cases differentiating a
cluster core and an extended cluster corona. Color-magnitude diagrams generally
show a definite main sequence that allows the confirmation of the physical
existence of the clusters and some of their characteristics. Two of the new
clusters seem to form a double system with a common origin. Several of the new
clusters challenge the claim of near completeness of the known OC population in
the distance range from 1.0 to 1.8 kpc of the Sun (Kharchenko et al. 2013).
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