Witness the Drama and Spectacle of Stellar Death With the Chandra X-Ray Observatory

These Chandra images reveal how stars end their life in majesty

Just as it has seen stars born, Chandra has witnessed their dying. As a star’s central engine begins to shut down amid a dearth of fuel, it starts to expel its outer atmosphere into the void. A very massive star dies in a far more spectacular fashion—as a supernova. Both the quiet and violent deaths of stars give rise to a new beginning: a rapidly expanding cloud of hot gas that shines brightly in X-rays.

Every fifty years or so, a massive star in our Galaxy blows itself up in a supernova explosion. Supernovas are some of the most violent events in the Universe, and the force of the explosion generates a blinding flash of radiation as well as shock waves that rumble across space.

This form of stellar death is not only about violence. Supernovas are also the primary means for seeding the Galaxy with elements such as carbon, nitrogen, oxygen, silicon, and iron that are necessary for life as we know it. Supernova explosions are responsible for disseminating most of the elements essential for life on Earth, which would otherwise be locked inside the furnaces of stars. We owe our very existence to these cosmic events: We are stardust indeed.

X-ray telescopes such as Chandra are important to the study of supernova remnants and the elements they produce because these events generate extremely high temperatures—millions of degrees— even thousands of years after the explosion. This means that many supernova remnants glow most strongly at X-ray wavelengths that are challenging to detect with other types of telescopes.

A supernova explosion usually leaves behind an extraordinarily dense object called a neutron star. In some cases, two neutron stars will remain bound to each other after their massive stellar predecessors explode. If the two neutron stars are close together, their orbits will shrink until they merge and generate a burst of gravitational waves—that is, ripples in space-time itself. In 2017, Chandra detected the afterglow of such an event, the first we have been able to document.

Here we celebrate one of Chandra’s greatest scientific legacies— a revolution in our understanding of how stars end their life in majesty. Some of the images that follow show the bodies of stars whose deaths have been witnessed by human beings, some centuries or even millennia ago. By pairing the information ancient astronomers gleaned with that from modern science, we can learn about these vital and remarkable objects that stretch across the Galaxy and beyond.

N132D is a supernova remnant in the Large Magellanic Cloud. The explosion of a massive star produced the horseshoe-shaped cloud of hot X-ray gas against a backdrop of thousands of stars in optical light. Shock waves produced by the explosion heated interstellar gas around the site to X-rayemitting temperatures of millions of degrees. Optical data reveal cooler gas and a small, bright crescent-shaped cloud of emission from hydrogen gas.

Where do most of the elements essential for life on Earth come from? They come from inside the furnaces of stars and the explosions that mark the end of some stars’ lives. Exploded stars and their remains show astronomers how stars produce and then disseminate many of the elements observed on Earth and in the cosmos at large. Cassiopeia A, one of the first objects Chandra observed after it was launched, is a spectacular supernova remnant that tells astronomers more about how these elements are dispersed into space.

When the star that created the Tycho's supernova remant exploded in 1572, it was so bright that it remains visible today. And though he wasn’t the first or only person to observe this stellar spectacle, the Danish astronomer Tycho Brahe wrote a book about his extensive observations of the event, gaining the honor of its being named after him. Today, astronomers using Chandra can study the intricate remains of this shattered star in X-ray light.

Circinus X-1 contains a neutron star—the collapsed core left behind after a star has exploded—in orbit with a massive star. Four partial rings appear as circles around Circinus X-1 in X-ray light (the unusual shape swing to the field of view of Chandra’s detectors). These rings are light echoes, similar to the sound echoes that we may experience on Earth. The echoes around Circinus X-1 are produced when a burst of X-rays from the star system reflects off of clouds of dust between Circinus X-1 and Earth.

Read more in Light from the Void, which is available from Smithsonian Books. Visit Smithsonian Books’ website to learn more about its publications and a full list of titles. 

Excerpt from Light from the Void Text © 2019 by Smithsonian Institution

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The SMITHSONIAN ASTROPHYSICAL OBSERVATORY is a part of the Smithsonian Institution which, in conjunction with the Harvard College Observatory, studies basic physical processes that determine the nature and evolution of the universe. Together they operate the Chandra X-Ray Observatory for NASA.