We report on the detection of Main Sequence stars belonging to the recently identified Canis Major galaxy in a field located at \simeq 4.2 \degr from the center of the stellar system .
With Main Sequence fitting we obtain a distance modulus ( m - M ) _ { 0 } = 14.5 \pm 0.3 to the dwarf , corresponding to a distance of D _ { \sun } \simeq 8.0 \pm 1.2 kpc , in full agreement with previous estimates based on the photometric parallax of M-giants .
From the comparison with theoretical isochrones we constrain the age of the main population of the Canis Major system in the range \sim 4 - 10 Gyr .
A blue plume of likely younger stars ( age < 1 - 2 Gyr ) is also identified .
The available Colour Magnitude Diagrams of open clusters that may be projected onto the main body of Canis Major are also briefly analyzed .
The position , distance and stellar population of the old open clusters AM-2 and Tombaugh 2 strongly suggest that they are physically associated with the Canis Major galaxy .
Using our own photometry and data from 2MASS and the GSC2.2 surveys we demonstrate that the claim by Momany et al .
that the CMa overdensity is entirely due to the Galactic warp is not supported by the existing observations , once all the available pieces of information are taken into account .
It is shown that the CMa overdensity clearly emerges at a heliocentric distance of \sim 8 kpc above any overdensity possibly produced by the Galactic warp .