Astronomers have discovered a massive molecular cloud that is also a huge possible star producer — of the celestial sort.
The cloud has been hiding in plain sight. Astronomers just needed the right tools to see one of the largest single structures in the sky and among the closest to the sun and Earth ever to be detected. By using a new technique, they detected the cloud's key component — molecular hydrogen, the scientists report in Nature Astronomy.
“The data showed glowing hydrogen molecules detected via fluorescence in the far ultraviolet,” Blakesley Burkhart, an astronomer at Rutgers University and an author of the paper, said in a press release. “This cloud is literally glowing in the dark.”
Molecular Cloud of Hydrogen
Hydrogen constitutes the most common element in molecular clouds, which primarily consist of gas and dust. That molecule is a necessary building block for stars, planets — and life. However, such clouds are typically found using radio and infrared observations that pick up the chemical signature for carbon dioxide.
This time, the scientists discovered the cloud they named “Eos,” after the Greek goddess who personifies dawn, by searching directly for far ultraviolet emissions of molecular hydrogen. They received a strong, clear signal.
This particular cloud's relative lack of carbon monoxide might explain why it remained hidden for so long, despite its size and proximity. The astronomers estimate its width the equivalent of 40 moons and its mass at about 3,400 times that of the sun. Because, at about 300 light years from Earth, Eos is relatively close, it presents a great observation to literally watch stars being born.
“When we look through our telescopes, we catch whole solar systems in the act of forming, but we don’t know in detail how that happens,” Burkhart said in the release. “Our discovery of Eos is exciting because we can now directly measure how molecular clouds are forming and dissociating, and how a galaxy begins to transform interstellar gas and dust into stars and planets.”
Read More: Some Stars Are Born From Fluffy Clouds in the Early Universe
NASA Mission: Eos
This new ability to detect molecular hydrogen may plant the seeds for many for findings to come. A NASA mission named Eos will look for molecular hydrogens in other parts of the galaxy. And the same team that has found, in Eos, the closest known molecular cloud may also have located the farthest known molecular cloud thus far, using the James Webb Space Telescope (JWST). Those results haven’t yet undergone peer review, but are available on a preprint server.
“Using JWST, we may have found the very furthest hydrogen molecules from the sun,” Burkhart said in the release. “So, we have found both some of the closest and farthest using far-ultraviolet emission.”
Read More: Galactic Collisions and Star Formations May Birth Distant Galaxies
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Nature Astronomy. A nearby dark molecular cloud in the Local Bubble revealed via H2 fluorescence
Astrophysics of Galaxies. A Tentative Detection of Molecular Hydrogen (H2) Emission Lines at Cosmic Dawn
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
