The Gould Belt, the de Vaucouleurs-Dolidze Belt, and the Orion Arm
  Based on masers with measured trigonometric parallaxes, we have redetermined
the spatial orientation parameters of the Local (Orion) arm. Using 23 sources
(the Gould Belt objects were excluded), we have found that their spatial
distribution can be approximated by a very narrow ellipsoid elongated in the
direction L_1=77.1+/-2.9^o whose symmetry plane is inclined to the Galactic
plane at an angle of 5.6+/-0.2^o. The longitude of the ascending node of the
symmetry plane is l_\Omega=70+/-3^o. A new estimate for the pitch angle of the
Local spiral arm has been obtained by an independent method: i=12.9+/-2.9^o.
Previously, a belt of young B stars, the de Vaucouleurs.Dolidze belt, was
pointed out on the celestial sphere with parameters close to such an
orientation. We have refined the spatial orientation parameters of this belt
based on a homogeneous sample of protostars. The de Vaucouleurs.Dolidze belt
can be identified with the Local arm, with the belt proper as a continuous band
on the celestial sphere like the Gould Belt being absent due to the
peculiarities of the spatial orientation of the Local arm. Using the entire
sample of 119 Galactic masers, we have shown that the third axis of their
position ellipsoid has no deviation from the direction to the Galactic pole:
B_3=89.7+/-0.1^o.
