Astronomers have finally discovered an object that has long been theorized: an hourglass-shaped magnetic field in a star forming region. The field is located in the protostellar system NGC IRAS 4A, which is located about 980 light-years from Earth in the constellation Perseus. Theorists predicted that the magnetic fields of collapsing clouds of gas and dust would form this hourglass shape because of the competing forces of magnetism and gravity.

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Is the significance that an hourglass magnetic field has been discovered, or that one has been discovered in a star forming region?

Regards,
Ian Tresman

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Ian Tresman
plasma-universe.com

The latter.

Well, I imagine a star-forming region is where one would look for a "system of two protostars," which is generating the field. (Even enlarged, the "hourglass" shape is a little tough to pick out. I wouldn't criticise an "artist's rendition" of this expected phenomenon....)

I suppose such a huge mass IS going to be "rubbing against itself" from gravitational interactions, thus creating some nontrivial magnetic fields....

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Everyone is entitled to his own opinion, but not his own facts.

The original press release is . If I read the article correctly, the only "role" of the magnetic field is that it is overcome by gravity, producing the hourglass shape. For the record, if we assume the cloud is a plasma, Bennett- or Z-pinching also results in an hourglass shape.

Cheers.

Joseph Miquel Girart also has a short presentation on "Magnetic Field and Star Formation" (PDF) in which he says that "... magnetic fields may play a crucial role in the formation, evolution of interstellar clouds and in the formation of stars". And that seems to be about it.

The Science magazine of the article "Magnetic Fields in the Formation of Sun-Like Stars" notes that "The magnetic field is substantially more important than turbulence in the evolution of the system". This makes sense if the molecular cloud contains a significant amount of plasma.

An earlier paper by Girart, "Interferometric Mapping of Magnetic Fields in Star-forming Regions II. NGC2024 FIR5" (2001) describes part of the "hourglass shape" as a "pinch".

Regards,
Ian Tresman

__________________
Ian Tresman
plasma-universe.com