Helical magnetic field surrounding the filamentary Orion Molecular Cloud

Astronomers announced Thursday what may be the first discovery of a helical magnetic field in interstellar space, coiled like a snake around a gas cloud in the constellation of Orion.

“You can think of this structure as a giant, magnetic Slinky wrapped around a long, finger-like interstellar cloud,” said Timothy Robishaw, a graduate student in astronomy at the University of California, Berkeley. “The magnetic field lines are like stretched rubber bands; the tension squeezes the cloud into its filamentary shape.”

“These results were incredibly exciting to me for a number of reasons,” Robishaw said. “There’s the scientific result of a helical field structure. Then, there’s the successful measurement: This type of observation is very difficult, and it took dozens of hours on the telescope just to understand how this enormous dish responds to the polarized radio waves that are the signature of a magnetic field.”

The questions raised by this discovery are as fascinating as the magnetic field, itself.