WHAT'S GOING ON IN CANIS MAJOR?

A. MOITINHO; G. CARRARO; R.A. VÁZQUEZ; G. BAUME; E.E. GIORGI

Lisboa (Portugal)

Congreso; 15th Portuguese National Meeting; 2005

We report the detection of a young stellar population ( 100 Myrs) in the back-ground of nine open clusters in the Third Galactic Quadrant. We find that the young background population in six cluster fields follow remarkably well the expected pattern of the Norma-Cygnus spiral arm as defined by CO clouds. This population is exactly the same population (the Blue Plume) recently detected in the direction of 3 intermediate-age open clusters located in the same direction, and suggested to be a 1-2 Gyr old population belonging to the Canis Major overdensity1,2. Both the distances and the ages we found are incompatible with this scenario.