When they “die,” many stars explode as supernovae, spewing a chaotic web of dust and gas into interstellar space. Space.

But the new image of the remnants of the dazzling “supernova” appears to be very different from what astronomers expected to see. This is the most unusual remnant ever found, and it may be a rare type of supernova that scientists have long been trying to decipher.

“I have been working with supernova remnants for 30 years and have never seen anything like it,” says Robert Fessen, an astronomer at Dartmouth College in New Hampshire.

850 year old fireworks

In 2013, amateur astronomer Dana Pacik discovered this image in archived infrared images from NASA’s large-scale survey. In the following decade, several groups studied the remaining star, known as Ra 30, with increasingly puzzling results.

In 2019, Vasily Garamadze, astronomer at Moscow State University. Lomonosov in Russia, and his colleagues discovered a very unusual star at the center of Ra 30. This star had a surface temperature of about 200,000 Kelvin.with a stellar wind moving outward at 16,000 kilometers per second, about 5% the speed of light.

“Stars don’t just blow at 10,000 miles per second,” Fessen says. 4,000 kilometers per second is not unheard of, he says, but 16,000 kilometers per second is a “wild measurement.”

Pa 30 came under scrutiny again in 2021, when Andreas Ritter, an astronomer at the University of Hong Kong, and colleagues suggested that the remnant is the descendant of a supernova that erupted in the sky about 850 years ago, in 1181. year, Chinese and Japanese astronomers observed the object for about six months, until it “disappeared” from the sky.

Fessen’s team later observed the remnant with the 2.4-meter Hiltner Telescope at Keith Peak Observatory in Arizona.

The data they collected confirmed that Pa 30 was indeed the remnant of a supernova observed in 1181, revealing hundreds of thin radiating ‘filaments’.

The image was unprecedented, as “under normal conditions” supernova remnants resemble those in the Cancer Nebula, or Tycho’s supernova, which resembles a tangle of “knots.”

But Pa 30 is a different, “amazing picture,” says Sharab Jha, an astronomer at Rutgers University in New Jersey. “I have never seen anything like it before. It’s really impressive.”

zombie stars

What could cause such a precipitate? In 2021, Ritter and colleagues hypothesized that this is a rare IACH-type supernova explosion.

A typical Type IA supernova occurs when a “white dwarf” consumes material from a nearby star (ss star system), eventually becoming so large that it can no longer support the extra weight, and explodes, scattering the material from within into the interstellar vacuum. But in an IACH-type supernova, the star somehow survives. “We often call these stars zombie”says I. This certainly expands the list of possible causes of an IAX-type supernova.

Such rare flashes are usually observed in distant galaxies millions of light years away from us. But Pa 30 is only 7.5 light-years away, in the neighborhood of our Milky Way, and future observations may shed more light on the unusual type of supernova.

Source Nature