The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star

This artist's visualization of GRB 221009A shows the narrow relativistic jets (emerging from a central black hole) that gave rise to the gamma-ray burst (GRB) and the expanding remains of the original star ejected via the supernova explosion. Credit: Aaron M. Geller / Northwestern / CIERA / IT Research Computing and Data Services

After a journey lasting about two billion years, photons from an extremely energetic gamma-ray burst (GRB) struck the sensors on the Neil Gehrels Swift Observatory and the Fermi Gamma-Ray Space Telescope on October 9th, 2022. The GRB lasted seven minutes but was visible for much longer. Even amateur astronomers spotted the powerful burst in visible frequencies.

It was so powerful that it affected Earth’s atmosphere, a remarkable feat for something more than two billion light-years away. It’s the brightest GRB ever observed, and since then, astrophysicists have searched for its source.

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This Supernova Lit Up the Sky in 1181. Here’s What it Looks Like Now

A composite image of the remnant of supernova 1181. A spherical bright nebula sits in the middle surrounded by a field of white dotted stars. Within the nebula several rays point out like fireworks from a central star. G. Ferrand and J. English (U. of Manitoba), NASA/Chandra/WISE, ESA/XMM, MDM/R.Fessen (Dartmouth College), Pan-STARRS

Historical astronomical records from China and Japan recorded a supernova explosion in the year 1181. It was in the constellation Cassiopeia and it shone as bright as the star Vega for 185 days. Modern astronomers took their cue from their long-gone counterparts and have been searching for its remnant.

But it took them time to find it because they were looking for the wrong thing.

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Finally, an Explanation for the “String of Pearls” in Supernova 1987A

A JWST NIRCam view of Supernova 1987a showing its string of pearls. The keyhole-shaped material at the heart is ejecta from the explosion. NASA, ESA, CSA, Mikako Matsuura (Cardiff University), Richard Arendt (NASA-GSFC, UMBC), Claes Fransson (Stockholm University), Josefin Larsson (KTH)
A JWST NIRCam view of Supernova 1987a showing its string of pearls. The keyhole-shaped material at the heart is ejecta from the explosion. NASA, ESA, CSA, Mikako Matsuura (Cardiff University), Richard Arendt (NASA-GSFC, UMBC), Claes Fransson (Stockholm University), Josefin Larsson (KTH)

Not long after the explosion of Supernova 1987a, astronomers were abuzz with predictions about how it might look in a few years. They suggested a pulsar would show up soon and many said that the expanding gas cloud would encounter earlier material ejected from the star. The collision would light up the region around the event and sparkle like diamonds.

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This is a 1.3 Gigapixel Image of a Supernova Remnant

This colorful web of wispy gas filaments is the Vela Supernova Remnant, an expanding nebula of cosmic debris left over from a massive star that exploded about 11,000 years ago. This image was taken with the Department of Energy-fabricated Dark Energy Camera (DECam), mounted on the US National Science Foundation's Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab. The striking reds, yellows, and blues in this image were achieved through the use of three DECam filters that each collect a specific color of light. Separate images were taken in each filter and then stacked on top of each other to produce this high-resolution image that contains 1.3 gigapixels and showcases the intricate web-like filaments snaking throughout the expanding cloud of gas.

Stars more massive than the Sun blow themselves to pieces at the end of their life. Usually leaving behind either a black hole, neutron star or pulsar they also scatter heavy elements across their host galaxy. One such star went supernova nearly 11,000 years ago creating the Vela Supernova Remnant. The resultant expanding cloud of debris covers almost 100 light years and would be twenty times the diameter of the full Moon. Astronomers have recently imaged the remnant with a 570 megapixel Dark Energy Camera (DECam) creating a stunning 1.3 gigapixel image. 

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Finally! Webb Finds a Neutron Star from Supernova 1987A

Supernova 1987A

I can remember seeing images of SN1987A as it developed back in 1987. It was the explosion of a star, a supernova in the Large Magellanic Cloud. Over the decades that followed, it was closely monitored in particular the expanding debris cloud. Predictions suggested there may be a neutron star or even a black hole at the core but the resolution of the telescopes was insufficient to pick anything up. Now we have the James Webb Space Telescope and using its more powerful technology, signs of a neutron star have been detected. 

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Even if We Can’t See the First Stars, We Could Detect Their Impact on the First Galaxies

Population III stars were the Universe's first stars. They were extremely massive, luminous stars, and many of them exploded as supernovae. How did they shape the early galaxies? Image Credit: DALL-E

For a long time, our understanding of the Universe’s first galaxies leaned heavily on theory. The light from that age only reached us after travelling for billions of years, and on the way, it was obscured and stretched into the infrared. Clues about the first galaxies are hidden in that messy light. Now that we have the James Webb Space Telescope and its powerful infrared capabilities, we’ve seen further into the past—and with more clarity—than ever before.

The JWST has imaged some of the very first galaxies, leading to a flood of new insights and challenging questions. But it can’t see individual stars.

How can astronomers detect their impact on the Universe’s first galaxies?

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Gravitationally Lensed Supernovae are Another Way to Measure the Expansion of the Universe

Hubble Space Telescope image of a gravitational lens.
This Hubble Space Telescope image shows the powerful gravity of a galaxy embedded in a massive cluster of galaxies producing multiple images of a single distant supernova far behind it.

Supernova are a fascinating phenomenon and have taught us much about the evolution of stars. The upcoming Nancy Grace Roman telescope will be hunting the elusive combination of supernovae in a gravitational lens system. With its observing field 200 times that of Hubble it stands a much greater chance of success. If sufficient lensed supernovae are found then they could be used to determine the expansion rate of the Universe. 

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Giant Star Seen 150 Days Before it Exploded as a Supernova

Artist's impression of a supernova remnant. Credit: ESA/Hubble

Supernovae are relatively rare. It might not seem like it, but that’s because they’re so bright we can see them in other galaxies a great distance away. In fact, in 2022, astronomers spotted a supernova over 10 billion light-years away.

Any time astronomers spot a supernova, it’s an opportunity to learn more about these rare, cataclysmic explosions. It’s especially valuable if astronomers can get a good look at the progenitor star before it explodes.

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This Galaxy Hosted One of the Most Powerful Supernovae Ever Seen

This NASA Hubble Space Telescope image is of the small galaxy known as UGC 5189A. This otherwise unremarkable galaxy was the site of an extraordinarly luminous supernova in 2010. ESA/Hubble & NASA, A. Filippenko

In 2010, an exceptionally luminous supernova exploded in a small galaxy about 150 million light-years away called UGC 5189A. The Hubble Space Telescope has kept its eye on this galaxy because of the extraordinary supernova, which for three years released more than 2.5 billion times the energy of our Sun in visible light alone.

Though the supernova, named SN 2010jl, died down years ago, astronomers are still watching its aftermath.

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Black Holes and Neutron Stars are Finally Linked to Supernovae

A star in a binary system dies in a catastrophic explosion. Such supernovae often result in neutron stars or black holes. Courtesy ESO/L. Calçada
This artist’s impression is based on the aftermath of a supernova explosion as seen by two teams of astronomers with both ESO’s Very Large Telescope (VLT) and ESO’s New Technology Telescope (NTT). The supernova observed, SN 2022jli, occurred when a massive star died in a fiery explosion, leaving behind a compact object — a neutron star or a black hole. This dying star, however, had a companion which was able to survive this violent event. The periodic interactions between the compact object and its companion left periodic signals in the data, which revealed that the supernova explosion had indeed resulted in a compact object.

Everybody knows that the explosive deaths of supermassive stars (called supernovae) lead to the creation of black holes or neutron stars, right? At least, that’s the evolutionary path that astronomers suggest happens. And, these compact objects exist throughout the Universe. But, no one’s ever seen the actual birth process of a neutron star or black hole in action before.

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