Spectra for transitions of molecules detected in the six Helix positions using IRAM 30 m. Individual spectra have been scaled by a multiplier indicated for each line to facilitate comparison. The x-axis indicates velocity with respect to the local standard of rest (V_LSR) and the y-axis is the antenna main-beam temperature (K). Vertical dotted lines mark the systemic velocity of individual emission features with respect to the entire nebula. Hyperfine structure lines are indicated in red. The two separate velocity features identified toward the Globule A, Helix Rim, and West positions represent emission from nearer and more distant clumps of gas. Positions are indicated on an HST optical image of the Helix (NASA, NOAO, ESA, the Hubble Helix Nebula Team, M. Meixner (STScI), and T.A. Rector (NRAO)), with the HCN (J = 1 → 0) beamsize (27.6″) and positions of our line survey observations as circles (globules A, B, C – from Huggins et al. 1992 – molecular Rim, East, and West positions).