supernovae

The largest component of the universe is something we know almost nothing about. The best and most accurate observations that cosmologists have gathered over decades show that all the matter around us, every single atom we see anywhere in the cosmos, makes up just 5 percent of all that exists. Another 27 percent is dark matter, which holds galaxies together. And everything else — a staggering 68 percent of the universe — is dark energy, a force that is responsible for the expansion of the universe. Without dark energy,…

On September 7, 2022, the Zwicky Transient Facility detected a new transient object in deep space, about one billion light-years from Earth. The object was very bright, and now, a team of astronomers believes it’s a star that’s come back from the dead.Dominic Monaghan on Attending Fan ConventionsThe object was a star: a luminous fast blue optical transient, or LFBOT for short. The star is named AT2022tsd, but affectionately called the Tasmanian Devil. Now, a team of researchers posit that the flaring activity exhibited by…

Dust, the building…

Two supernovae 22 million light-years away ejected dust into their region of the universe, Webb Space Telescope observations reveal, indicating that violent stellar deaths could give rise to new star systems.Webb Telescope Images the Pillars of CreationSupernovae are luminous stellar deaths; when some stars die, they explode outwards, spewing their material across the cosmos.The supernovae currently in question are SN 2004et and SN 2017eaw, and both are in NGC 6946 — the Fireworks Galaxy. Webb imaged the two objects using…

The extraterrestrial processes responsible for influencing the diversity of life forms are usually invisible to the human eye. The Milky Way is where large stars explode, leading to supernova remnants whose shock fronts accelerate cosmic ray particles to high energies. Cosmic rays find their way to the solar system, where some collide with the atmosphere producing cascades of secondary particles which ionize the atmosphere. Ions influence the formation of clouds which ultimately affect climate. Therefore, changes in…

Don't you just hate it when you're just minding your own business, and a star suddenly decides to go supernova? Well, good news: Scientists have figured out what these stars look like right before they die.According to new simulations, the massive stars that are the progenitors of neutron stars dim dramatically in the last few months before they explode. So, if a massive star fades into complete obscurity without fanfare, the odds are good that there's a supernova on the horizon.Red supergiant stars clocking in at around…

It often feels like when people die, they leave a void behind. In the case of massive stars, that happens to be physically true.A new analysis of the tenuous gas that drifts between the stars in the Milky Way galaxy has revealed the imprint of bubbles that expand into space when a massive star goes supernova at the end of its life. These ghostly traces, scientists say, record a history of star death and the rotation of the Milky Way.  The space between the stars is not entirely empty. In those gaps in space drifts gas,…

When it comes to going out with style, nothing comes close to the end of a white dwarf. Their thermonuclear self-destruction ranks among the most powerful explosions in the cosmos, forcing the star to wink out of existence in a blaze of glory.  At least, that's the idea. A discovery confirms some white dwarfs fake their deaths with a lackluster performance, only to go on shining even brighter than before.Ten years ago, supernova SN 2012Z was spotted in the nearby spiral galaxy NGC 1309, glowing briefly in a swan song…

Scientists from the RIKEN Cluster for Pioneering Research have used computer modeling to show how a hypothesized type of supernova would evolve on the scale of thousands of years, giving researchers a way to look for examples of supernovae of this model, known as “D6.”Supernovae are important for cosmology because one type, Ia, is used as a “standard candle” that allows distance to be measured. In fact, they were used for the measurements that revealed, surprisingly to first observers, that the universe’s expansion is…

Multiple star systems are very common in the Milky Way. While most of these systems are binary systems consisting of two stars, others contain three, four, or even six stars.These systems tend to be pretty stable since unstable systems tend to break apart or merge fairly quickly, but sometimes you can get a kind of meta-stable system. One that lasts long enough for stars to evolve while still being stable in the end. And that end could be a supernova.  It all comes down to gravitational dynamics. In Newtonian physics,…