Odin finds elusive oxygen molecule

The constellation of Ophiuchus hosts dense molecular clouds in the Milky Way, where new stars and their planets are currently born. The Odin satellite has received a signal from this direction, indicating for the first time the presence of molecular oxygen (O₂) in such clouds. Credit: Odin team (Background image: Alex Mellinger).

Molecular oxygen has for the first time been detected in interstellar space by an international group of scientists using the Swedish Odin space observatory.

- The result is important for understanding the complex development of interstellar clouds forming stars and planets, says Bengt Larsson, researcher at Stockholm Observatory and one of the persons behind the study.
Previous attempts to find the elusive molecule made by observatories both on ground and in space were unsuccessful, and it was then realized that the abundance of oxygen was much lower than assumed before the search started. Just how low has not been known until the Odin measurements. The molecule was found in the dense gas cloud rho Oph A in the constellation of Ophiuchus at a distance of about 500 light years. The discovery is published in an article in Astronomy & Astrophysics.

For more information, see the Swedish Space Corporation's press release.