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We present narrow-band optical and near-IR imaging and optical long-slitspectroscopic observations of Hu1-2, a Galactic planetary nebula (PN) with apair of [N II]-bright, fast-moving (> 340 km/s) bipolar knots.Intermediate-dispersion spectra are used to derive physical conditions andabundances across the nebula, and high-dispersion spectra to study thespatio-kinematical structure. Generally Hu1-2 has high He/H (~0.14) and N/Oratios (~0.9), typical of Type I PNe. On the other hand, its abundances of O,Ne, S, and Ar are low as compared with the average abundances of Galactic bulgeand disc PNe. The position-velocity maps can be generally described as anhour-glass shaped nebula with bipolar expansion, although the morphology andkinematics of the innermost regions cannot be satisfactorily explained with asimple, tilted equatorial torus. The spatio-kinematical study confines theinclination angle of its major axis to be within 10 degrees of the plane ofsky. As in the irradiated bow-shocks of IC4634 and NGC7009, there is a clearstratification in the emission peaks of [O III], H_alpha, and [N II] in thenorthwest (NW) knot of Hu1-2. Fast collimated outflows in PNe exhibit higherexcitation than other low-ionization structures. This is particularly the casefor the bipolar knots of Hu1-2, with He II emission levels above those ofcollimated outflows in other Galactic PNe. The excitation of the knots in Hu1-2is consistent with the combined effects of shocks and UV radiation from thecentral star. The mechanical energy and luminosity of the knots are similar tothose observed in the PNe known to harbor a post-common envelope (post-CE)close binary central star.

Hu1-2: a metal-poor bipolar planetary nebula with fast collimated outflows