An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Calculated fractional abundance of C5H4 (allowing for various isomers) as a function of time. The horizontal dashed line corresponds to the sum of the observed abundances of the two C5H4 isomers (CH3C4H and H2CCCHCCH) detected in TMC-1.