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Published online by Cambridge University Press: 26 May 2016
Up to now, ten planetary nebulae are regarded as halo planetary nebulae (halo PNe). We obtained low- and moderate-dispersion spectra of the spatially resolved halo planetary nebula H4-1 in the wavelength region of λλ3700-6800 Å with the Cassegrain Spectrograph of 74-inch telescope at Okayama Astronomical Observatory. In the moderate dispersion observation, we were able to obtain [O III] λλ4959,5007 and Hα of H4-1 at several position angles (P.A.). The image was spatially resolved and its apparent angluar size should be less than 10″.0.