Rotational diagram of the observed lines of CH₂CHCN. The black and red points correspond to a-type and b-type transitions, respectively. A rotational temperature of 4.3±0.2 K is derived. The estimated b-component of the dipolar moment is 0.80±0.03 D. The blue and green points correspond to the b-type transitions when using µ_b = 0.687 D (Krásnicki & Kisiel 2011) and 0.894 D (Stolze & Sutter 1985), respectively. Their error bars are identical to those of the red points.