Interstellar space: scientists detect a ring-shaped sulfur molecule for the first time

Astronomers report detecting thiepine (C6H6S), a 13-atom ring-shaped sulfur-bearing molecule, in the molecular cloud G+0.693-0.027 near the Milky Way’s center. The identification was confirmed by matching laboratory spectra from an electrical-discharge synthesis to radio observations from IRAM and Yebes telescopes.

Astronomers have identified thiepine (2,5-cyclohexadiene-1-thione, C6H6S) in the molecular cloud G+0.693-0.027 near the center of the Milky Way. This work was led by researchers at the Max Planck Institute for Extraterrestrial Physics and the CSIC-INTA Centro de Astrobiología. The team produced the molecule in the laboratory by applying a 1,000-volt electrical discharge to liquid thiophenol and recorded its radio-frequency spectrum with a custom spectrometer. They then compared those laboratory measurements to radio data taken with the IRAM 30-meter and Yebes 40-meter telescopes. The report describes this as the largest sulfur-bearing molecule detected beyond Earth to date. Key findings: - The detected molecule is thiepine (C6H6S), a six-membered, 13-atom sulfur-bearing ring. - The astronomical source is the molecular cloud G+0.693-0.027, a star-forming region about 27,000 light-years from Earth. - Laboratory synthesis used an electrical discharge on thiophenol to produce thiepine and measure its spectrum. - Observational data came from the IRAM 30-meter and Yebes 40-meter radio telescopes in Spain. - Authors note the molecule is structurally related to compounds found in meteorite and comet samples and describe this as a link between astrochemistry and molecules associated with life on Earth. Summary: The detection fills a gap between the larger sulfur-bearing organics known from meteorites and the smaller sulfur compounds previously observed in space, and the authors present the laboratory–telescope match as confirmation of the identification. Undetermined at this time.