Unblended and slightly blended transitions of s-H₂C=CHOH detected towards G+0.693. For a description of the colours displayed in the plot, see Fig. 2. The spectroscopic information and the derived parameters from the best LTE fit of these lines are reported in Table 3. The frequencies of the lines are shown in the upper part of each panel, while the red asterisks indicate the transitions that contribute to the identification of s-H₂C=CHOH. Dotted black lines indicate the 3 × rms level in intensity in the spectra. Dotted red lines show the detectability limit in integrated area defined as , with N the number of channels across the linewidth.