Lines of H₂NC observed in L483 (see parameters in Table 1). In red we show the computed synthetic spectra for a column density of H₂NC of 10¹² cm⁻², ortho-to-para ratio of 3, rotational temperature of 4.0 K, full width at half maximum of 0.35 km s⁻¹ (except for the 3_0,3–2_0,2 lines, in which case a value of 0.19 km s⁻¹ was adopted), and an emission size that fills the IRAM 30 m main beam. Vertical blue lines indicate the position of CCD lines (see Appendix A).