Abundance of HC₅N as a function of the abundance of HC₃N in different protostellar and cold sources: inner (black arrow) and outer envelope (T₂₀) of IRAS 16293 (black filled circle) presented in this work, warm carbon-chain chemistry (WCCC) sources (blue diamond; Sakai et al. 2008; Jørgensen et al. 2004), first hydrostatic core (FHSC) source (green triangle; Cordiner et al. 2012), hot cores sources (cross; Schöier et al. 2002; Esplugues et al. 2013), and Galactic Centre clouds (red square; Marr et al. 1993; Aladro et al. 2011).