===== On the Detection of MgC₂ in Circumstellar Envelopes ===== Magnesiacyclopropynylidene, MgC₂, is somewhat related to silacyclopropynylidene, SiC₂.\\ P. B. Changala, H. Gupta, J. Cernicharo, J. R. Pardo, M. Agúndez, C. Cabezas, B. Tercero, M. Guélin, and M. C. McCarthy\\ reported on the\\ **[[https://doi.org/10.3847/2041-8213/aca144|Laboratory and Astronomical Discovery of Magnesium Dicarbide, MgC₂]]**\\ //Astrophys. J. Lett// **940**, Art. No. L42 (2022).\\ Ten //a//-type lines with 1 ≤ //J// ≤ 7 and //K_a// ≤ 4 between 41 and 150 GHz were identified for the main ²⁴Mg isotopolog employing the Yebes 40 m and IRAM 30 m dishes in the couses of molecular line surveys of CW Leonis. These lines have good to reasonable signal-to-noise ratios, and several lines are unblended. One and three lines were identified for the ²⁵Mg and ²⁶Mg minor isotopologs, respectively. The isotopic ratios are compatible with solar values within uncertainties. The derived MgC₂ : MgC₂H : MgC₄H : MgC₆H abundance raios are about 1 : 2 : 22 : 20.\\ \\ ---- Contributor(s): H. S. P. Müller; 12, 2022 ----