  The astrophysical parameters of the open star cluster Mayer 3 have been
estimated using the Newtonian focus (f/4.84) of the 1.88 m Telescope of
Kottamia Observatory in Egypt. The VRI observations have been carried out down
to a limiting magnitude of V ~ 20 mag. To emphasize the main astrophysical
parameters, Near-Infra Red, Two Micron All Sky Survey (2MASS-JHK) database has
been used. Analyzing the color-magnitude diagrams and radial density
distribution of Mayer 3, the cluster's age, reddening, distance from the Sun,
the limited border, core and tidal radii are evaluated. The photometrical
membership, the Galactocentric coordinates from the Galactic center and
Galactic plane are estimated. Luminosity - mass functions, and the total mass
of the cluster are established. Finally, the relaxation time estimation
conclude that Mayer 3 is not dynamically relaxed yet.
