Chupina Open Clusters

[lamperti]

I ran across this name in a Sky Tools print out of asteroid Prokne for last night. There are three open clusters near Messier 67 in Cancer: Chupina 1, 3 and 5. They are not listed in Uranometria or Millenium atlases. There is an article describing them that states, "The old stellar cluster
M67 still apparently contains clumpy outer structure (Chupina & Vereshchagin 1998)". Amateur images do not seem to capture them.

Anyone else ever hear of these?

Al

[Steve Gottlieb]

Never heard of them before, but the Chupina & Vereshchagin paper is here (http://ads.ari.uni-heidelberg.de/cgi-bin/nph-iarticle_query?1998A%26A...334..552C&data_type=PDF _HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf). The abstract reads...

"Several star clumps are detected inside the low density extended corona of the open cluster M 67 with the help of the method “the distances to nearest neighbour analysis”, elaborated earlier for analysis of galaxy distributions. The groups include from 5 to 11 stars and have mean sizes from 0.5 to 1.2 pc. We check the reality of their existence by statistical estimates based on kinematical data analysis. It is shown that at least one clump is not a random star density fluctuation. The question of the origin of these substructures remains open."

So, 5 groups each with a handful of stars surrounding M67 and only one confirmed as not a random fluctuation. Don't see how these can be considered true clusters, though perhaps there's been later research.

[KidOrion]

These are also plotted in the TriAtlas, for what it's worth.