In this work we revisit the issue of the rotation speed of the spiral arms and the location of the corotation radius of our Galaxy .
This research was performed using homogeneous data set of young open clusters ( age < 50 Myr ) determined from Gaia DR2 data .
The stellar astrometric membership were determined using proper motions and parallaxes , taking into account the full covariance matrix .
The distance , age , reddening and metallicity of the clusters were determined by our non subjective multidimensional global optimization tool to fit theoretical isochrones to Gaia DR2 photometric data .
The rotation speed of the arms is obtained from the relation between age and angular distance of the birthplace of the clusters to the present-day position of the arms .
Using the clusters belonging to the Sagittarius-Carina , Local and Perseus arms , and adopting the Galactic parameters R _ { 0 } = 8.3 kpc and V _ { 0 } = 240 km s ^ { -1 } , we determine a pattern speed of 28.2 \pm 2.1 km s ^ { -1 } kpc ^ { -1 } , with no difference between the arms .
This implies that the corotation radius is R _ { c } = 8.51 \pm 0.64 kpc , close to the solar Galactic orbit ( R _ { c } / R _ { 0 } = 1.02 \pm 0.07 ) .