One of this year's newly discovered molecules is the ketenyl radical, HCCO, which was detected by
Agúndez et al. toward two dark clouds,
the protostar L433
and the starless core Lupus-1 (which
has also been found to contain abundant
interstellar anions). The IRAM
30m telescope was used for the astronomical
observations. To date, this detection has not been confirmed by subsequent observations.
Turner & Sears searched for HCCO in
the dark molecular cloud
TMC-1 in the late 1980s without success.
The ketenyl (or ethynyloxy) radical is a
near prolate asymmetric top (κ=-0.99). Its rotational spectrum was characterized by
Endo & Hirota in work published in 1987.
The Cologne Database lists
348 lines for HCCO.