Three Incredible Telescopes Looked At The Butterfly Nebula To Learn Where Earth Came From

The Butterfly Nebula is among the most beautiful nebulae out there. It's a planetary nebula formed by an aging star throwing out layers of plasma before turning into a white dwarf. New observations have allowed astronomers to track the formation of cosmic dust in this peculiar environment, understanding where the building blocks of planets, including our own, come from.

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At the center of the nebula, also known as NGC 6302, sits one of the hottest stellar objects known: a white dwarf – the end stage of a star not massive enough to go supernova – shining with a temperature of over 220,000°C (almost 400,000°F). Its exact location was not known, but using JWST, which sees in infrared so can peer through the dust that shrouds it, obscuring our view, astronomers have finally confirmed it. 

Using JWST, the team could see through the dusty torus, the donut-shaped region around the white dwarf, for the first time. They discovered wildly different dust components. The torus is the dark part that makes up the “body” of the butterfly in the optical images. 

JWST did not just see through it, though, it also worked out what’s in it. But it was not alone in this work. The team combined new JWST observations in the mid-infrared with optical and near-infrared data from Hubble and longer-wavelength observations from the Atacama Large Millimeter/submillimeter Array (ALMA). Together, they provide an incredible view into the nebula's more salient structure.

"We were able to see both cool gemstones formed in calm, long-lasting zones and fiery grime created in violent, fast-moving parts of space, all within a single object,” lead researcher Dr Mikako Matsuura, of Cardiff University, said in a statement.

"This discovery is a big step forward in understanding how the basic materials of planets come together."

JWST and ALMA have shown structure within the torus, with data supporting the presence of large crystalline silicates like quartz as well as irregularly shaped dust grains.

When we say large, we are still talking micron-sized crystals, but those are far larger than the usual cosmic dust. This suggests that the silicate dust has been growing and accumulating for a very long time. Outside the torus, the team discovered the presence of iron and nickel in jets blasting out from the star in opposite directions.

The team also found polycyclic aromatic hydrocarbons (PAH), honeycomb carbon structures that on Earth are usually formed in smoke. These possibly formed as the hot winds from the white dwarf slammed into the layer it had released when it was still a full-blown star. If the observations are correct, this might be the first-ever evidence of PAHs forming in an oxygen-rich planetary nebula.

The study is published in the Monthly Notices Of The Royal Astronomical Society.