NASA’s James Webb Space Telescope has revealed the long-hidden core of the Butterfly Nebula, offering the clearest view yet of one of the Milky Way’s most striking planetary nebulae.
The nebula, formally known as NGC 6302, lies 3,400 light-years away in the constellation Scorpius. Discovered in 1826 by astronomer William Herschel, it is distinguished by two luminous lobes resembling butterfly wings and a dense dust band across its center that has long obscured its central star.
Webb’s Mid-Infrared Instrument (MIRI) was used to peer through the dust, employing its integral field unit mode to capture images in multiple wavelengths. The observation revealed the nebula’s core star, estimated to have a scorching surface temperature of 220,000 Kelvin. According to researchers, this makes it “one of the hottest of all the known central stars in a planetary nebula in the Milky Way galaxy.”
The analysis also shed light on the composition of the central dust band, which contains crystalline silicate, including quartz, as well as dust grains about a millionth of a meter in size. Beyond the dust, scientists identified jets of iron and nickel streaming outward in opposite directions, along with signals from polycyclic aromatic hydrocarbons (PAHs). The discovery of PAHs in an oxygen-rich nebula could help refine understanding of how such molecules form in space.
The findings were made by combining Webb’s data with earlier observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Together, the results provide the most detailed portrait yet of the Butterfly Nebula’s complex structure.