From June 1982 through February 1984, three groups independently observed methyl diacetylene
(CH3C4H) toward TMC-1.
All three groups sought and found the K=0 and K=1 components of two consecutive rotational transitions and
reported their discoveries in 1984. The first report was published in May 1984 by
Walmsley et al. based on the most recent
observations (Feb 1984) using the
Effelsberg 100-m Radio Telescope.
In July 1984, MacLeod et al. published their
observations from June and July 1982 made at the
Haystack Radio Observatory.
Finally, in November 1984 Loren et al. published
their observations of December 1983 and January 1984 with the NRAO
P R Jewell
Two close cousins of methyldiacetylene (or 1,3-pentadidyne) have also been observed,
methyacetylene (propyne) and
methyltriacetylene (1,3,5-heptatriyne). The
next member of the series,
has only been observed in the lab to date.