In 1604, astronomers saw the sudden death of a star in the distant universe by its supernova. Today, more than 400 years later, the pun of that explosion can still be seen. This aftermath is known as Kepler’s supernova.
Recently, NASA’s Chandra X-ray Observatory captured images of material that jumped out of this supernova explosion at faster speeds than 20 million miles per hour, which is about 25,000 times faster than the speed of sound on Earth.
On Wednesday, NASA released a cosmic video sequence, consisting of four Chandra images, with details of moving nodes linked to the supernova. The related findings were published in the journal in May Astrophysics.
The star in question is a white dwarf star that lies about 20,000 light-years away in the Milky Way. The sudden death was named as the Kepler supernova after the German astronomer Johannes Kepler, who was among the group of astronomers to first observe the explosion.
The explosion is known as Type la supernova. This is when a dense white dwarf star is a critical mass limit more than the interaction with a companion star. As a result, the white dwarf star is crushed and the remains are launched outward.
Track the speed of waste – With Chandra’s latest observations, the research team tracked the velocity of 15 small knots of pun from the supernova.
The fastest node of the Kepler supernova had a starting velocity of 23 million miles per hour, the highest speed ever discovered of remnants of supernova remnants in X-rays, according to the study.
Meanwhile, the average speed of the nodes is about 10 million miles per hour, and the explosion wave is expanding to about 15 million miles per hour.
These high speeds are only measured days and weeks after the first explosion of a supernova. However, because the Kepler supernova has been going strong for more than 400 years, the images indicate that the pound has not slowed down due to collisions with surrounding material since the first catalyst.
The researchers also used Chandra images obtained in the years 2000, 2004, 2006, and 2014 to detect changes in the positions of the nodes to measure their velocity.
However, they are still very unsure how to explain the high speed material. The assumption, for now, is that the supernova was particularly bright, or that the surrounding material is “lumpy”, allowing the pun to escape from areas that have a low density and do not slow down.
Abstract: We report our measurements of the bulk radial velocity of a sample of small, metal-rich ejecta nodes in Kepler’s Supernova Remnant (SNR). We measure the Doppler shift of the He-like Si Kα line energy in the spectra of these nodes based on our Chandra High-Energy Transmission Grating Spectrometer (HETGS) observation to estimate their radial velocities. We estimate high radial velocities of up to .000 8,000 km s – 1 for some of these ejecta knots. We also measure accurate motions for our support based on the archived Chandra Advanced CCD Imaging Spectrometer (ACIS) data taken in 2000, 2006, and 2014. Our measured radial velocities and appropriate motions indicate that some of these ejecta nodes almost freely expanding to ∼ 400 years since the explosion. The fastest moving nodes show accurate motions up to ∼ 0.2 arcseconds per year. Assuming that these high-speed ejecta nodes precede the SNR’s forward shock, we estimate the distance to Kepler’s SNR to be 4.4 to 7.5 kpc. We find that the ejecta nodes in our sample have an average space velocity of vs 4,600 km s – 1 (at a distance of 6 kpc). We found that 8 of the 15 ejecta nodes from our sample showed a statistically significant (at 90% confidence level) redshifted spectrum, compared to only two with a blueshifted spectrum. This may suggest an asymmetry in the ejecta distribution in Kepler’s SNR along the line of sight, however, a larger sample size is needed to confirm this result.
