Conclusion
The O-, B- stars and A0 – A5 stars from the Hipparcos catalogue have been studied by their position, proper motion, parallax and what combined with radial velocity data. In the XYZ coordinate system, the space volume of the Gould Belt has been studied and that is also compared with the model proposed by Guillout et al. (1998). X = [- 500, 180], Y = [- 500, 0], and the distribution in the Z direction is in the range between - 200 pc to 200 pc. Besides, the Gould Belt projects on the XZ plane and YZ plane forming angles 16.5 degree and 7.2 degree with respect to the projected galactic plane. In the YZ plane, a belt might not belong to the Gould Belt forming an angle about 38° and the angle projected on the XZ plane is similar to that of the Gould Belt. The angles could be changed when they are transferred to the Gould Belt system. The better fitting model in the work is from Guillout et al. (1998). The model shows three Eulerian angles are -50°, 20°, and 87°, while the values of the OB stars in the research are - 48°, 22°, and 84°.
On the proper motion vector point diagram, it seems that two groups with different kinematical characteristic and one of them contains quantities of stars which might be the members of the Gould Belt. On the XYZ diagram of the stars chosen from the sample OBA5 of proper motion vector point diagram, the distribution has displayed most stars of the group are located on the Gould Belt.
Furthermore, there is the similarity on the velocity diagram and XYZ diagram.
The Gould belt could be reflected by space position usually for OB stars, however, the Gould belt is also reflected roughly for main sequence stars with spectral down to A5. Furthermore, the kinematical characteristic, proper motion or space velocity, is helpful to stand out the Gould Belt.
