Summary: Astronomers have created the first three-dimensional map of peculiar filaments emanating from a supernova remnant observed in 1181 CE. Using advanced spectral imaging technology at the W.M. Keck Observatory, researchers tracked these mysterious structures moving at approximately 1,000 kilometers per second, confirming their origin from a rare partial stellar explosion that left behind a ‘zombie star.’
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In the year 1181, skygazers in China and Japan documented a new star appearing in the constellation Cassiopeia. This celestial visitor, visible for nearly six months, marked a rare stellar explosion known as a supernova. Now, over 840 years later, scientists have mapped its remnants in unprecedented detail, revealing strange filaments that resemble a cosmic dandelion.
From Historical Records to Modern Discovery
The journey to understanding this ancient explosion took a surprising turn in 2013 when amateur astronomer Dana Patchick discovered a nebula while examining images from the Wide-field Infrared Survey Explorer (WISE). This nebula, designated Pa 30, was later confirmed to be the remnant of the 1181 supernova. By 2023, researchers identified unusual filaments extending from the remnant, setting the stage for a deeper investigation.
Mapping a Cosmic Dandelion
Using the Caltech-built Keck Cosmic Web Imager (KCWI) at the W.M. Keck Observatory in Hawai’i, astronomers have now created an unprecedented three-dimensional view of these mysterious filaments.
“A standard image of the supernova remnant would be like a static photo of a fireworks display,” explains Caltech Professor of Physics Christopher Martin, who led the team that built KCWI. “KCWI gives us something like a ‘movie’ since we can measure the motion of the explosion’s embers as they streak outward from the central explosion.”
The research, published in The Astrophysical Journal Letters under the title “Expansion properties of the young supernova type Iax remnant Pa 30 revealed,” offers new insights into an unusual type of stellar explosion. Unlike typical supernovae where a white dwarf star is completely destroyed, this event was a partial explosion known as a Type Iax supernova.
“Because this was a failed explosion, it was fainter than normal supernovae, which has been shown to be consistent with the historical records,” says Ilaria Caiazzo, co-lead author and assistant professor at the Institute of Science and Technology Austria.
The team’s measurements revealed that the filaments are moving at approximately 1,000 kilometers per second. “We find the material in the filaments is expanding ballistically,” notes Tim Cunningham, co-lead author and NASA Hubble Fellow. “This means that the material has not been slowed down, or sped up since the explosion. From the measured velocities, looking back in time you can pinpoint the explosion to almost exactly the year 1181.”
While the mapping revealed a large cavity within the spherical structure and evidence of an asymmetric explosion, the formation mechanism of the filaments remains unclear. “A reverse shock wave may be condensing surrounding dust into filaments, but we don’t know yet,” Cunningham adds. “The morphology of this object is very strange and fascinating.”
Quiz
- What year was the supernova first observed?
- What makes this supernova unusual compared to typical stellar explosions?
- How fast are the filaments moving through space?
Answers:
- 1181 CE
- It was a partial explosion (Type Iax) that left behind a ‘zombie star’
- Approximately 1,000 kilometers per second
Glossary of Terms
- Supernova: A powerful explosion marking the death of a star
- White Dwarf: A dense, dead star that represents the final evolutionary state of stars like our Sun
- Type Iax Supernova: A rare type of partial stellar explosion where part of the star survives
- Nebula: A cloud of gas and dust in space
- Spectral Information: Data about light wavelengths that reveals motion and composition of celestial objects
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Further Reading: The Astrophysical Journal Letters
