Space and astronomy news
Twenty thousand years ago, a star in the constellation Cygnus went supernova. Like all supernovae, the explosion released a staggering amount of energy. The explosion sent a powerful shockwave into the surrounding space at half a million miles per hour, and it shows no signs of slowing down.
For twenty years, the Hubble Space Telescope has been watching some of the action.
Continue reading “Astronomers Have Been Watching a Supernova’s Debris Cloud Expand for Decades with Hubble”
In 2009 a giant star 25 times more massive than the Sun simply…vanished. Okay, it wasn’t quite that simple. It underwent a period of brightening, increasing in luminosity to a million Suns, just as if it was ready to explode into a supernova. But then it faded rather than exploding. And when astronomers tried to see the star, using the Large Binocular Telescope (LBT), Hubble, and the Spitzer space telescope, they couldn’t see anything.
The star, known as N6946-BH1, is now considered a failed supernova. The BH1 in its name is due to the fact that astronomers think the star collapsed to become a black hole rather than triggering a supernova. But that has been conjecture. All we’ve known for sure is that it brightened for a time then grew too dim for our telescopes to observe. But that has changed, thanks to the James Webb Space Telescope (JWST).
Continue reading “Astronomers Watched a Massive Star Just… Disappear. Now JWST Might Have Some Answers”
A recent study examines how the Earth was hit by blasts from supernovae (plural form of supernova (SN)) that occurred 3 million years ago (Mya) and 7 Mya with the goal of ascertaining the distances of where these blasts originated. Using the live (not decaying) radioactive isotope 60-Fe, which is produced from supernovae, a team of researchers at the University of Illinois was able to determine the approximate astronomical distances to the blasts, which they refer to as Pliocene Supernova (SN Plio, 3 Mya) and the Miocene Supernova (SN Mio, 7 Mya).
Continue reading “Supernovae Struck the Earth 3 Million and 7 Million Years Ago”
When the largest stars in the Universe run out of fuel, they detonate as supernovae, collapsing inward and leaving behind a neutron star, black hole, or just wholly vaporizing. What’s happening inside the unfolding explosion is difficult to understand, and especially so for so-called exotic supernovae, the rarest and brightest types of stellar explosions.
To better understand the dynamics of these rare supernovae, astronomers are using powerful supercomputers to simulate the process. After years of real-world research and millions of hours of supercomputer computing time, researchers have completed the first ever high-definition, 3D hydrodynamic simulation of exotic supernovae.
Continue reading “This 3D Simulation of a Supernova Needed 5 Million Hours of Supercomputing”
The thing about a supernova is that you never know when it might occur. Supernovae are triggered either by a collision with another star or when the interior of a massive star becomes depleted of nuclear fuel and begins a rapid collapse. Neither of these show any major optical changes before the explosion, so we are left to scan the sky in the hopes of catching one in its early stages. But that could soon change.
Continue reading “A New Observatory Will Spot Core-Collapse Supernovae Before They Explode”
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.
Continue reading “The Closest Supernova Seen in the Modern Era, Examined by JWST”
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.
Continue reading “Did this Supernova Explode Twice?”
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.
Continue reading “Supernovae are the Source of Dust in Early Galaxies”
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.
Continue reading “Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens”
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.
Continue reading “Gemini North Returns to Service Just in Time to See a New Supernova”