Update of membership and mean proper motion of open clusters from UCAC5 catalog

We present mean proper motions and membership probabilities of individual stars for optically visible open clusters, which have been determined using data from the UCAC5 catalog. This follows our previous studies with the UCAC2 and UCAC4 catalogs, but now using improved proper motions in the GAIA reference frame. In the present study results were obtained for a sample of 1108 open clusters. For five clusters, this is the first determination of mean proper motion, and for the whole sample, we present results with a much larger number of identified astrometric member stars than on previous studies. It is the last update of our Open cluster Catalog based on proper motion data only. Future updates will count on astrometric, photometric and spectroscopic GAIA data as input for analyses.Comment: 7 pages, 3 figures, 2 tables, 4 equations; accepted for publication in 2018 May 25 in the MNRA

Analytical r-mode solution with gravitational radiation reaction force

We present and discuss the analytical r-mode solution to the linearized hydrodynamic equations of a slowly rotating, Newtonian, barotropic, non-magnetized, perfect-fluid star in which the gravitational radiation reaction force is present.Comment: 3 pages, in Proceedings of the 5th International Workshop "New Worlds in Astroparticle Physics", Faro, Portugal, 8-10 January 200

Y(3940) as a Mixed Charmonium-Molecule State

Using the QCD sum rules approach we study the mass and decay width of the channel $J/\psi + \omega$ for the $Y(3940)$ state. We assume that it can be described by a mixed charmonium-molecule scalar state, $(\chi_{c0})-(D^\ast D^\ast)$ current, with $J^{PC} = 0^{++}$ quantum numbers. For the mixing angle $(76.0 \pm 5.0)^0$, we obtain the value $M = (3.95 \pm 0.11)$ GeV for the mass, which is in good agreement with the experimental mass of the $Y(3940)$ state. For the decay width into the channel $Y \rightarrow J/\psi + \omega$, we find the value $\Gamma_Y = (1.7 \pm 0.6)$ MeV, which is also compatible with the experimental data. We thus conclude that the present description of the $Y(3940)$ as a mixed charmonium-molecule state is a possible scenario to explain the structure of this state.Comment: 8 pages, 5 figures, 1 Tabl