supernova Archives

September 3, 2023September 3, 2023 by Brian Koberlein

The Closest Supernova Seen in the Modern Era, Examined by JWST

SN 1987a as seen by JWST's Near-Infrared Camera. Credit: NASA, ESA, CSA, M. Matsuura, R. Arendt, C. Fransson

In November of 1572, Tycho Brahe noticed a new star in the constellation Cassiopeia. It was the first supernova to be observed in detail by Western astronomers and became known as Tycho’s Supernova. Earlier supernovae had been observed by Chinese and Japanese astronomers, but Tycho’s observations demonstrated to the Catholic world that the stars were not constant and unchanging as Aristotle presumed. Just three decades later, in 1604, Johannes Kepler watched a supernova in the constellation Ophiuchus brighten and fade. There have been no observed supernovae in the Milky Way since then.

August 31, 2023August 31, 2023 by Evan Gough

Did this Supernova Explode Twice?

Artist view of a binary system before a type Ia supernova. Credit: Adam Makarenko/W. M. Keck Observatory

All supernovae are exploding stars. But the nature of a supernova explosion varies quite a bit. One type, named Type 1a supernovae, involves a binary star where one of the pair is a white dwarf. And while supernovae of all types usually involve a single explosion, astronomers have found something that breaks that mould: A Type 1a supernova that may have detonated twice.

July 8, 2023July 8, 2023 by Brian Koberlein

Supernovae are the Source of Dust in Early Galaxies

Images of SN 2004et and SN 2017eaw. Credit: NASA, ESA, CSA, Ori Fox (STScI), Melissa Shahbandeh (STScI), Alyssa Pagan (STScI)

Every now and then there’s an interesting discovery that helps us fill in a gap in our understanding of the universe. In the case of this latest discovery, we now have confirmation of a process we’ve long assumed, but have had little direct evidence for. It all has to do with cosmic dust.

June 18, 2023June 18, 2023 by Matt Williams

Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens

A gravitational lens caused by a galaxy in the foreground leading to an "Einstein Cross." Credit: NASA/ESA/STScI

Measuring cosmic distances is challenging, and astronomers rely on multiple methods and tools to do it – collectively referred to as the Cosmic Distance Ladder. One particularly crucial tool is Type Ia supernovae, which occur in binary systems where one star (a white dwarf) consumes matter from a companion (often a red giant) until it reaches the Chandrasekhar Limit and collapses under its own mass. As these stars blow off their outer layers in a massive explosion, they temporarily outshine everything in the background.

In a recent study, an international team of researchers led by Ariel Goobar of the Oskar Klein Centre at Stockholm University discovered an unusual Type Ia supernova, SN Zwicky (SN 2022qmx). In an unusual twist, the team observed an “Einstein Cross,” an unusual phenomenon predicted by Einstein’s Theory of General Relativity where the presence of a gravitational lens in the foreground amplifies light from a distant object. This was a major accomplishment for the team since it involved observing two very rare astronomical events that happened to coincide.

June 9, 2023June 9, 2023 by Nancy Atkinson

Gemini North Returns to Service Just in Time to See a New Supernova

A new supernova, SN 2023ixf, seen in the lower left of this image from the newly refurbished Gemini North telescope, is the closest supernova seen in the past five years. The supernova, discovered on May 19, 2023, is located along one of the spiral arms of the Pinwheel Galaxy. Credit: International Gemini Observatory/NOIRLab/NSF/AURA

The 8-meter Gemini North telescope has been brought back online after seven months of repairs and refurbishment of its primary mirror. The timing couldn’t have been better, as the telescope was able to capture the brand-new supernova in the famous Pinwheel Galaxy. The bright supernova was first discovered on May 19th, and telescopes worldwide have been revealing its secrets.

June 2, 2023June 2, 2023 by Evan Gough

Betelgeuse is Almost 50% Brighter Than Normal. What’s Going On?

The red supergiant Betelgeuse. Its activity can be confounding, and new research suggests that the star could've consumed a smaller companion star. Image credit: Hubble Space Telescope. Image Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

Whenever something happens with Betelgeuse, speculations about it exploding as a supernova proliferate. It would be cool if it did. We’re far enough away to suffer no consequences, so it’s fun to imagine the sky lighting up like that for months.

Now the red supergiant star has brightened by almost 50%, and that has the speculation ramping up again.

May 20, 2023May 20, 2023 by Brian Koberlein

Not All Type 1a Supernovae are Created Equally

Supernovae are brilliant explosions that can, for a time, outshine an entire galaxy. They come in two broad types: Type I and Type II. Type II supernovae are what are known as core-collapse supernovae. They occur when a massive dying star fuses ever heavier elements in its core until it runs out of energy options and its core collapses under its own weight, which triggers the explosion. Type I supernovae occur when…well, it’s complicated. But we’re learning more thanks to a new observation by radio astronomers.

May 19, 2023May 19, 2023 by Matt Williams

The Largest Explosion Ever Seen in the Universe

Artist impression of a black hole accretion. Credit: John A. Paice.

Throughout recorded history, humans have looked up at the night sky and witnessed the major astronomical events known as a “supernova.” The name, still used by astronomers, referred to the belief that these bursts of light in the “firmament” signaled the birth of a “new star.” With the birth of telescopes and modern astronomy, we have since learned that supernovae are what occur at the end of a star’s lifecycle. At this point, when a star has exhausted its hydrogen and helium fuel, it experiences gravitational collapse at its center.

This leads to a tremendous explosion that can be seen billions of light-years distant, releasing tremendous amounts of energy and blowing the star’s outer layers off. Thanks to an international team of astronomers led by the University of Southhampton, the most powerful cosmic explosion has been confirmed! The stellar explosion, AT2021lwx, took place about 8 billion light-years away in the constellation Vulpecula and was over ten times brighter than any supernova ever observed and 100 times brighter than all the stars in the Milky Way combined!

April 28, 2023April 28, 2023 by Brian Koberlein

You Don't Want to Be Within 160 Light-Years of a Supernova

A nearby supernova desolates a nearby habitable planet. Credit: NASA/CXC/M. Weiss

Supernovae are incredibly common in the universe. Based on observations of isotopes such as aluminum-26, we know that a supernova occurs on average about every fifty years in the Milky Way alone. A supernova can outshine a galaxy, so you wouldn’t want your habitable planet to be a few light years away when it goes off. Fortunately, most supernovae have occurred very far away from Earth, so we haven’t had to concern ourselves with wearing sunscreen at night. But it does raise an interesting question. When it comes to supernovae, how close is too close? As a recent study shows, the answer depends on the type of supernova.

April 10, 2023April 10, 2023 by Carolyn Collins Petersen

It’s Time for Supernova Remnant Cassiopeia A to Get the JWST Treatment

Cassiopeia A (Cas A) is a supernova remnant. It has been observed many times. This new image uses data from Webb’s Mid-Infrared Instrument (MIRI) to reveal Cas A in a new light. Credits: NASA, ESA, CSA, D. D. Milisavljevic (Purdue), T. Temim (Princeton), I. De Looze (Ghent University). Image Processing: J. DePasquale (STScI)

Ready for another stunning image from JWST? How about a peek inside a supernova remnant? Not just any stellar debris, but a highly detailed view of the leftovers from the explosion that created Cassiopeia A. The latest image is giving astronomers an up-close and personal look at what happened to a supermassive star some 11,000 light-years away from us. It may also help answer questions about the existence of cosmic dust, particularly in the early Universe.