Tag: supernova remnant

The growing X-ray shell of the 1604 Kepler supernova

3:31 pm

Kepler's supernovae remnant over time
Click to see movie.

Cool image time! Astronomers now have created a short movie from X-ray data compiled by the Chandra X-ray Observatory accumulated during the past quarter century showing the expansion of the cloud ejected from the 1604 supernova discovered by astronomer Johannes Kepler.

The two images to the right are the first and last frames in the movie. Though they appear the same, if you look closely you will see that in the more recent image the cloud is larger. From the press release:

Supernova remnants, the debris fields left behind after a stellar explosion, often glow strongly in X-ray light because the material has been heated to millions of degrees from the blast. The remnant is located in our galaxy, about 17,000 light-years from Earth, allowing Chandra to make … detailed images of the debris and how it changes with time. This latest video includes its X-ray data from 2000, 2004, 2006, 2014, and 2025. This makes it the longest-spanning video that Chandra has ever released, enabled by Chandra’s longevity. Only Chandra, with its sharp X-ray images and longevity, can see changes like those seen here.

…The researchers used the video to show that the fastest parts of the remnant are traveling at about 13.8 million miles per hour (2% of the speed of light), moving toward the bottom of the image. Meanwhile, the slowest parts are traveling toward the top at about 4 million miles per hour (0.5% of the speed of light). This large difference in speed is because the gas that the remnant is plowing into toward the top of the image is denser than the gas toward the bottom. This gives scientists information about the environments into which this star exploded.

This is one of the curses that astronomers live with. Things take a loooong time to unfold, often several generations. Thus Kepler might see this supernova when it erupts, but the explosion continues for many centuries.

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New data detects potassium and chlorine in Cassiopeia supernova remnant

11:30 am

The Cassiopeia supernova remnant
Click for original.

Using the Japanese orbiting XRISM space telescope, astronomers have now detected evidence of both potassium and chlorine in the ancient Cassiopeia supernova remnant.

The picture to the right, reduced to post here, shows the evidence for potassium in the remnant, overlaid onto an image of Cassiopeia produced by combining data from X-ray data from Chandra, infrared data from Webb, and optical data from Hubble. The green grid boxes indicate strong evidence of potassium, while the yellow grid boxes indicate weaker evidence.

The roughly circular Cas A supernova remnant spans about 10 light-years, is over 340 years old, and has a superdense neutron star at its center — the remains of the original star’s core. Scientists using NASA’s Chandra X-ray Observatory had previously identified signatures of iron, silicon, sulfur, and other elements within Cas A.

In the hunt for other elements, the team used the Resolve instrument aboard XRISM to look at the remnant twice in December 2023. The researchers were able to pick out the signatures for chlorine and potassium, determining that the remnant contains ratios much higher than expected. Resolve also detected a possible indication of phosphorous, which was previously discovered in Cas A by infrared missions.

The orientation and position of these grid boxes on the face of the expanding supernova remnant suggest the original star and explosion might have formed unevenly.

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Webb takes infrared false-color image of supernova remnant Cassiopeia A

8:54 am

Cass A in infrared
Click for original image.

Using the Webb Space Telescope, astronomers have obtained the first wide full infrared view of the supernova remnant Cassiopeia A, the remains of a supernova that occurred about 11,000 years ago. That image is to the right, reduced to post here.

The most noticeable colors in Webb’s newest image are clumps represented in bright orange and light pink that make up the inner shell of the supernova remnant. Webb’s razor-sharp view can detect the tiniest knots of gas, comprised of sulfur, oxygen, argon, and neon from the star itself. Embedded in this gas is a mixture of dust and molecules, which will eventually become components of new stars and planetary systems. Some filaments of debris are too tiny to be resolved by even Webb, meaning they are comparable to or less than 10 billion miles across (around 100 astronomical units). In comparison, the entirety of Cas A spans 10 light-years across, or 60 trillion miles.

…When comparing Webb’s new near-infrared view of Cas A with the mid-infrared view, its inner cavity and outermost shell are curiously devoid of color. The outskirts of the main inner shell, which appeared as a deep orange and red in the MIRI image, now look like smoke from a campfire. This marks where the supernova blast wave is ramming into surrounding circumstellar material. The dust in the circumstellar material is too cool to be detected directly at near-infrared wavelengths, but lights up in the mid-infrared.

The four rectangles mark specific features of particular interest, with #4, dubbed by the scientists Baby Cas, the most intriguing.

This is a light echo, where light from the star’s long-ago explosion has reached and is warming distant dust, which is glowing as it cools down. The intricacy of the dust pattern, and Baby Cas A’s apparent proximity to Cas A itself, are particularly intriguing to researchers. In actuality, Baby Cas A is located about 170 light-years behind the supernova remnant.

By comparing this infrared view with Hubble’s optical and Chandra’s X-ray views, astronomers will be able to better decipher Cas A’s make-up and geometry.

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Hubble data shows expansion of supernova remnant

9:57 am

Cygnus loop filament

Astronomers have created a four-second long movie using Hubble images collected over twenty years that shows the expansion of one filament in the Cygnus Loop supernova remnant, the explosion of which is thought to have occurred 20,000 years ago.

The picture above is one frame of that movie. The filament is estimated to be two light years in length.

By analyzing the shock’s location, astronomers found that the shock hasn’t slowed down at all in the last 20 years, and is speeding into interstellar space at over half a million miles per hour – fast enough to travel from Earth to the Moon in less than half an hour. While this seems incredibly fast, it’s actually on the slow end for the speed of a supernova shock wave.

Two versions of the movie are at the link, with the longer providing excellent context.

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