CTIO/NOIRLab/DOE/NSF
In early December 185 CE, Chinese astronomers recorded a bright “guest star” in the night sky that had been shining for eight months in the direction of Alpha Centauri before fading out — presumably. Closest recorded supernova in the historical record. a photo above This gives us a rare glimpse of the whole. torn remains From that explosion that happened a long time ago, it was also captured Dark energy camera (DECam), mounted on a four-meter telescope at the Cerro Tololo Pan-American Observatory in the Andes Mountains of Chile. DECam has been in operation since 2012 and although it was originally designed to be part of a work in progress Dark Energy Research, which is also available for other astronomers to use in their research. This new, broad view of the SN 185 remnant should help astronomers learn more about the evolution of stars.
As we wrote earlier, there are two types of known supernovae, depending on the mass of the parent star. An iron-core supernova explosion huge stars (greater than 10 solar masses), which collapse with such force that it causes a massive and catastrophic explosion. The temperatures and pressures are so high that the carbon in the star’s core melts. This stops the collapse of the nucleus, at least temporarily, and this process continues, over and over, with progressively heavier atomic nuclei. When it finally runs out of fuel, the iron core (so far) collapses into a black hole or neutron star.
Then there is a Type Ia supernova. Smaller stars (up to about eight solar masses) gradually cool into dense ash cores known as white dwarfs. If a white dwarf that has run out of nuclear fuel is part of a binary system, it can absorb matter from its partner, adding mass until its core reaches temperatures high enough for carbon fusion to occur. These are the brightest supernovae and they also shine with remarkably consistent peak brightness, which makes them invaluable.”Standard candles“For astronomers to determine cosmic distances.
Precious few details about SN185 are available at Later Han book, except for “bamboo mat size” and “display different colors, beautiful or not”. Astronomers suspected a possible connection between SN 185 and the remnant structure, which it has dubbed RCW86However, they have long assumed that the event that formed RCW 86 was a supernova from the collapse of the core, which would take about 10,000 years for the remaining structure to reach its current form.
In 2006, new X-ray data collected by the European Space Agency’s XMM-Newton Observatory and NASA’s Chandra X-ray Observatory showed that RCW 86 is much younger than previously thought: about 2,000 years old. The authors were able to calculate how quickly the shock wave was expanding within RCW 86. They found that there were denser regions where the shock wave was expanding more slowly, leading the astronomers to believe the remnant was older than it really is. But there are other areas where the shock wave is still inside the bubble—and still expanding rapidly—that provide a more accurate estimate of RCW 86’s age.
The new age estimate greatly strengthened the case that RCW 86 is the remnant of SN 185. In this case, SN 185 may be a Type Ia supernova, a conclusion based in part on the discovery of a large amount of iron in the remnant. A white dwarf star devouring its partner in a binary system produces high-speed winds that push gas and dust out and create a cavity before the white dwarf explodes. This allowed all of this debris to expand very quickly to create the impressive wrecked structure it exists today.
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