The Proper Motions of the Warm Molecular Hydrogen Gas in Herbig-Haro

摘要

We have measured the proper motions of three molecular hydrogen (v = 10 2.121 μm) knots in the Herbig-Haro 1 object using a 4.4 yr baseline (19921997). The HH 1F knot, which probably corresponds to the tip of the working surface of HH 1, has a proper motion of 0.19 ± 0.10 (arcsec yr~-1) and a position angle of 315_-25~+29 deg. This motion is comparable to that determined in the atomic emission lines of Hα and [S Ⅱ] λλ671731, and confirms that the warm molecular H_2 gas is partaking of the same motion as the atomicionic gas.