Study reveals complex chemistry inside ‘stellar nurseries’

(Phys.org) This mosaic combines several observations of the Taurus Molecular Cloud performed by ESA’s Herschel observatory. Located about 450 light-years from us, in the constellation Taurus, the Bull, this vast complex of interstellar clouds is where a myriad of stars are being born, and is the closest large region of star formation. Credit: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech),CC BY-SA 3.0 IGO

An international team of researchers has uncovered what might be a critical step in the chemical evolution of molecules in cosmic “stellar nurseries.” In these vast clouds of cold gas and dust in space, trillions of molecules swirl together over millions of years. The collapse of these interstellar clouds eventually gives rise to young stars and planets.

Like human bodies, stellar nurseries contain a lot of organic molecules, which are made up mostly of carbon and hydrogen atoms. The group’s results, published Feb. 6 in the journal Nature Astronomy, reveal how certain large organic molecules may form inside these clouds. It’s one tiny step in the eons-long chemical journey that carbon atoms undergo—forming in the hearts of dying stars, then becoming part of planets, living organisms on Earth and perhaps beyond.

“In these cold molecular clouds, you’re creating the first building blocks that will, in the end, form stars and planets,” said Jordy Bouwman, research associate at the Laboratory for Atmospheric and Space Physics (LASP) and assistant professor in the Department of Chemistry at the University of Colorado Boulder.

For the new study, Bouwman and his colleagues took a deep dive into one stellar nursery in particular: the Taurus Molecular Cloud (TMC-1). This region sits in the constellation Taurus and is roughly 440 light years (more than 2 quadrillion miles) from Earth. This chemically complex environment is an example of what astronomers call an “accreting starless core.” Its cloud has begun to collapse, but scientists haven’t yet detected embryonic stars emerging inside it.

The team’s findings hinge on a deceptively simple molecule called ortho-benzyne. Drawing on experiments on Earth and computer simulations, the researchers showed that this molecule can readily combine with others in space to form a wide range of larger organic molecules. (continues)

Research publication: Jordy Bouwman, Five-membered ring compounds from ortho-benzyne + methyl radical reaction under interstellar conditions, Nature Astronomy (2023). DOI: 10.1038/s41550-023-01893-2. www.nature.com/articles/s41550-023-01893-2

Some more relatively recent developments in the field of astrochemistry:

Ingredients for Life Appear in Stellar Nurseries Long Before Stars are Born

Lab produces building blocks to DNA and RNA in deep space conditions

Complex organic molecules detected in the starless core Lynds 1521E