Magnetic Field May Shape 'Blooming' Star as it Transforms into a Planetary Nebula

A star is currently "blooming" in the southern sky as it begins to push out a jet of charged particles. Now, scientists have captured this event using a CSIRO telescope, revealing a bit more about why this old star is ejecting these particles.

The star itself is called IRAS 15445-5449 and lies about 23,000 light-years away in the southern constellation Triangulum Australe, the Southern Triangle. While other older stars are known to have jets, though, this is the first one where radio waves tell scientists that the jet is held together by a strong magnetic field. This, in particular, may show what exactly makes these jets switch on in the first place.

In order to detect this blooming star, the scientists used CSIRO's Australia Telescope Compact Array to examine the radio waves from the star's jets. The scientists were able to see that this flowering star is currently in the process of turning into a planetary nebula, a large glowing object that early astronomers though looked like planets. In actuality, planetary nebulae are stars late in their lives that have shed much of their gas into space. This gas glows and can create some of the most beautiful objects in the universe.

The "jet" phase of a planetary nebula is actually just a blink of an eye in a star's life. It only lasts a few hundred years. Afterward, a planetary nebula is left behind, showing a surprising symmetry that scientists are still trying to tease apart.

It's possible that the outflowing gas is shaped by the presence of a companion to the old star, either another star or a planet. It's also possible that the magnetic field of the old star could cause this symmetry.

"The magnetic field may get twisted up as the star shrinks, perhaps launching these jets," said Jessica Chapman, one of the researchers, in a news release.

Currently, further research is needed before scientists can determine what helps spawn these jets and what shapes planetary nebulae. Yet this newest study is an important step in the right direction for better understanding how planetary nebulae form.

The findings are published in the Monthly Notices of the Royal Astronomical Society.