Reports on the Detection of 1,3-Pentadiyne in the ISM

The 1,3-pentadiyne molecule CH₃C₄H, aka methyldiacetylene, had been identified in spectra recorded toward TMC-1 by two groups independently and at almost the same time
J. M. MacLeod, L. W. Avery, N. W. Broten,
The detection of interstellar methyldiacetylene (CH₃C₄H)
Astrophys. J. 282, L89–L92 (1984);
C. M. Walmsley, P. R. Jewell, L. E. Snyder, and G. Winnewisser,
Detection of interstellar methyldiacetylene (CH₃C₄H) in the dark dust cloud TMC 1
Astron. Astrophys. 184, L11–L14 (1984).