Hα spectra of SR 12 c from five individual datasets. All spectra show blueshifted peaks and are asymmetric with respect to the systemic velocity of −6.8 ± 3.0 km s⁻¹ (A. Santamaría-Miranda et al. 2018; see also Figure 2). While spectra #1 and #2 show peaks at approximately −30 km s⁻¹, the subsequent spectra show peaks at approximately −10 km s⁻¹. A difference of −20 km s⁻¹ is significant. While the velocity resolution in our observations are 6.1–7.5 km s⁻¹, the data were binned to a velocity resolution of 10.5 km s⁻¹ to increase SNR. Unidentified systematic effects may be present at approximately −175 and +175 km s⁻¹ (see Section 2). The error bars are shown only for the first spectrum for presentation purposes. The absolute flux is provided as a reference (see Section 2).