Somewhere in deep space, there is a beautiful cosmic weed, blasting its symbolic pollen away from its core at incredible speeds. For almost 900 years, the big explosion in the atmosphere that caused this weed to bloom was a mystery. Now, the telescope at the edge offers our best look at the results.
The weed is actually a nebula, called the Pa 30 nebula, and its structure has certain characteristics. In 2023, astronomers from Dartmouth College and Louisiana State University described the matter that erupted from the explosion as clumped together into filaments, sprouting from the center like a dandelion. Following that study, other astronomers have now mapped those filaments for the first time.
Human interest in the nebula can be traced back to the year 1181, when astronomers in Japan and China both recorded sightings of a new star. Six months later, it was gone, but not forgotten. In 2013, a novice astronomer named Dana Patchick was looking at images taken by NASA’s Wide-field Infrared Survey Explorer, a now-defunct infrared space telescope. He identified a nebula in the area where the star may have been, a distance of 7,500 light years from Earth, in the constellation Cassiopeia. In the following decade, astronomers concluded that the Pa 30 nebula was probably the remnant of a supernova, which ancient astronomers had seen all those years ago.
Nebulas are brightly shining, and often large, clusters of matter, such as ionized gas and cosmic dust. But not all nebulae are the same. Some are made up of the remnants of stars, which die in massive explosions. That’s what happened in the case of the Pa 30 Nebula, and some of the results are unique among known nebulae. At its core, a remnant of its progenitor star remains, with a surface temperature of 360,000 degrees Fahrenheit (200,000 Celsius). For reference, our Sun has a surface temperature of about 10,000 degrees Fahrenheit (5,500 Celsius). The star also shoots objects away from it at an incredible speed of 620 kilometers (1,000 miles) per second.
“We find that the objects in the strings are growing in a strange way,” said Tim Cunningham, a NASA Hubble Fellow at the Harvard and Smithsonian Center for Astrophysics, in a statement. “This means that the cargo has never been lowered or accelerated since the explosion. From the measured velocity, if you look back in time, you can trace the eruption to about the year 1181.”
Cunningham and his colleagues wanted to get a better idea of the shape of those fibers. They turned to a machine in Hawaii called the Keck Cosmic Web Imager (KCWI), which can detect light in the visible spectrum. Different colors vibrate with different amounts of energy. For example, blue has higher energy levels compared to red. The difference in energy allowed astronomers to tell which object was moving toward Earth, and which was moving away. The result was a 3D map of the filaments of the nebula. The shape is asymmetrical, indicating that the original eruption was also asymmetrical. There is also a strange hole of nothingness, up to 3 light-years across, between the central star’s remnant and the filaments, which may have been the result of an explosion that destroyed everything that was so close to its surface. (It should be noted that the Pa 30 nebula is not alone in being an oddly shaped celestial body.)
https://www.youtube.com/watch?v=XP9UCezhnQ
“A typical image of a supernova remnant would be like a still image of a fireworks display,” said Christopher Martin, a professor of physics at Caltech, who worked on the subsequent study, published in The Astrophysical Journal Letters. “KCWI gives us something like a ‘movie’ as we can measure the movement of the embers of the eruption as it flows outwards from the central eruption.”
The question that remains is why this nebula took this shape. Cunningham said it might be because the shock wave compressed the fast dust into beams, but nothing is certain. Even after nearly a millennium, some mysteries still persist.
Source link
