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.Continue reading “Not All Type 1a Supernovae are Created Equally”
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!Continue reading “The Largest Explosion Ever Seen in the Universe”
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.Continue reading “You Don't Want to Be Within 160 Light-Years of a Supernova”
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.Continue reading “It’s Time for Supernova Remnant Cassiopeia A to Get the JWST Treatment”
Life on Earth has been around for a long time—at least 3.8 billion years. During that time, it evolved significantly. Why has biodiversity here changed so much? A new study proposes a startling idea. Some major diversity changes are linked to supernovae—the explosions of massive stars. If true, it shows that cosmic processes and astrophysical events can influence the evolution of life on our planet.Continue reading “Did Supernovae Help Push Life to Become More Diverse?”
The first written record of a supernova comes from Chinese astrologers in the year 185. Those records say a ‘guest star’ lit up the sky for about eight months. We now know that it was a supernova.
All that remains is a ring of debris named RCW 86, and astronomers working with the DECam (Dark Energy Camera) used it to examine the debris ring and the aftermath of the supernova.Continue reading “The Dark Energy Camera Captures the Remains of an Ancient Supernova”
The NASA/European Space Agency (ESA)/Canadian Space Agency (CSA) James Webb Space Telescope (JWST) mission continues to dazzle and amaze with every image it beams back to Earth, and a recent observation depicting not one, not two, but three images of the same galaxy has been no different, as they proudly tweeted on February 28, 2023.Continue reading “JWST Sees the Same Supernova Three Times in an Epic Gravitational Lens”
When stars die, they spread the elements they’ve created in their cores out to space. But, other objects and processes in space also create elements. Eventually, that “star stuff” scatters across the galaxy in giant debris clouds. Later on—sometimes millions of years later—it settles onto planets. What’s the missing link between element creation and deposition on some distant world?Continue reading “Some Elements Arrived on Earth by Surfing Supernova Shock Waves”
Kilonovae are extraordinarily rare. Astronomers think there are only about 10 of them in the Milky Way. But they’re extraordinarily powerful and produce heavy elements like uranium, thorium, and gold.
Usually, astronomers spot them after they’ve merged and emitted powerful gamma-ray bursts (GRBs.) But astronomers using the SMARTS telescope say they’ve spotted a kilonova progenitor for the first time.Continue reading “This Binary System is Destined to Become a Kilonova”
The venerable Hubble Space Telescope has given us so much during the history of its service (32 years, 7 months, 6 days, and counting!) Even after all these years, the versatile and sophisticated observatory is still pulling its weight alongside more recent addition, like the James Webb Space Telescope (JWST) and other members of NASA’s Great Observatories family. In addition to how it is still conducting observation campaigns, astronomers and astrophysicists are combing through the volumes of data Hubble accumulated over the years to find even more hidden gems.
A team led by Caltech’s recently made some very interesting finds in the Hubble archives, where they observed the sites of six supernovae to learn more about their progenitor stars. Their observations were part of the Hubble Space Telescope Snapshot program, where astronomers use HST images to chart the life cycle and evolution of stars, galaxies, and other celestial objects. From this, they were able to place constraints on the size, mass, and other key characteristics of the progenitor stars and what they experienced before experiencing core collapse.Continue reading “By Looking Back Through Hubble Data, Astronomers Have Identified six Massive Stars Before They Exploded as Core-Collapse Supernovae”