Planetary nebula are some of nature’s most stunning visual displays. The name is confusing since they’re the remains of stars, not planets. But that doesn’t detract from their status as objects of captivating beauty and intense scientific study.
Continue reading “See the Southern Ring Nebula in 3D”This Supernova Lit Up the Sky in 1181. Here’s What it Looks Like Now
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.
Continue reading “This Supernova Lit Up the Sky in 1181. Here’s What it Looks Like Now”M87's Jet is Triggering Novae
Everyone loves a good mystery, and astronomers have just uncovered a new one in a nearby supermassive galaxy called M87. Like most galaxies, M87 regularly plays host to a smattering of stellar explosions called novae, each the result of a star stealing material from a neighbour. M87 also features a massive jet of plasma blasting out into deep space from the galactic core. These phenomena: the jet and the novae, are unrelated astronomical occurrences, or so scientists believed. But astronomers recently discovered that the novae in M87 seem to be uncharacteristically aligned along the jet, instead of scattered randomly throughout the galaxy. Is the jet somehow triggering nova explosions?
It might be, but the mystery is: how?
Continue reading “M87's Jet is Triggering Novae”Did this Supernova Explode Twice?
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?”These are the Fastest Stars in the Galaxy
Until recently, there were only ten known stars on trajectories that will allow them to escape the Milky Way Galaxy, thrown astray by powerful supernova explosions. A new study using data from ESA’s Gaia survey this June has revealed an additional six runaways, two of which break the record for the fastest radial velocity of any runaway star ever seen: 1694 km/s and 2285 km/s.
Continue reading “These are the Fastest Stars in the Galaxy”The Mass of a Single Star (other than the Sun) has Been Directly Measured for the First Time
How do you measure an object’s weight from a distance? You could guess at its distance and therefore derive its size. Maybe you could further speculate about its density, which would eventually lead to an estimated weight. But these are far from the exact empirical studies that astrophysicists would like to have when trying to understand the weight of stars. Now, for the first time ever, scientists have empirically discovered the weight of a distant single star, and they did so using gravitational lensing.
Continue reading “The Mass of a Single Star (other than the Sun) has Been Directly Measured for the First Time”Two Stars Orbiting Each Other Every 51 Minutes. This Can’t End Well
We don’t have to worry too much about our Sun. It can burn our skin, and it can emit potent doses of charged material—called Solar storms—that can damage electrical systems. But the Sun is alone up there, making things simpler and more predictable.
Other stars are locked in relationships with one another as binary pairs. A new study found a binary pair of stars that are so close to each other they orbit every 51 minutes, the shortest orbit ever seen in a binary system. Their proximity to one another spells trouble.
Continue reading “Two Stars Orbiting Each Other Every 51 Minutes. This Can’t End Well”Astronomers Finally Catch a Nova Detonating on a White Dwarf as it's Happening
On July 7, 2020, the X-ray instrument eROSITA captured an astronomical event that – until then – had only been theorized and never seen. It saw the detonation of a nova on a white dwarf star, which produced a so-called fireball explosion of X-rays.
“It was to some extent a fortunate coincidence, really,” said Ole König from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), who led the team of scientists who have published a new paper on the discovery. “These X-ray flashes last only a few hours and are almost impossible to predict, but the observational instrument must be pointed directly at the explosion at exactly the right time.”
Continue reading “Astronomers Finally Catch a Nova Detonating on a White Dwarf as it's Happening”If There are Dyson Spheres Around White Dwarfs, We Should be Able to Detect Them
Searching for Dyson spheres, rings, or swarms remains a preoccupation of many astronomers. If there are any out there, they will eventually be found, and the person or research team to do so will go down in history for making one of the most momentous discoveries in the history of humanity. If you’re interested in claiming that accolade for yourself, an excellent place to look may be around white dwarfs. At least, that’s the theory put forward in a new paper by Benjamin Zuckerman, a now-retired professor of astrophysics at UCLA.
Continue reading “If There are Dyson Spheres Around White Dwarfs, We Should be Able to Detect Them”A New Kind of Stellar Explosion Has Been Discovered: Micronovae
The most energetic explosions in the Universe come from stars called supernovae. These galactic bombs have the energy of about 1028 mega-tons. After they detonate, the only thing left behind is either a neutron star or black hole. Another type of stellar explosion is known as a nova which has much less energy and covers the surface of a white dwarf.
Now, a team of astronomers recently discovered a new type of stellar explosion akin to supernovae and novae but with much less energy, and they’re calling it a micronova.
Continue reading “A New Kind of Stellar Explosion Has Been Discovered: Micronovae”