When a flash of light appears somewhere in the sky, astronomers notice. When it appears in a region of the sky not known to host a stellar object that’s flashed before, they really sit up and take notice. In astronomical parlance, objects that emit flashing light are called transients.
Earlier this year, astronomers spotted a transient that flashed with the light of a trillion Suns.
Young protostars are wrapped in what could be called a womb of gas and dust. The gas and dust nearest to them form a circumstellar disk as the stars grow. The disk is a reservoir of material that the star accretes as it grows.
But these stars don’t feed in a predictable rhythm. Sometimes, they experience feeding frenzies, periods of time they accrete lots of material from the disk at once. When that happens, they flare in bright bursts, “burping” as they absorb more material.
Can a star have a solid surface? It might sound counterintuitive. But human intuition is a response to our evolution on Earth, where up is up, down is down, and there are three states of matter. Intuition fails when it confronts the cosmos.
All stars are composed of mostly hydrogen and helium, but most stars also have measurable amounts of heavier elements, which astronomers lump into the category of “metals.” Our Sun has more metals than most stars because the nebula from which it formed was the remnant debris of earlier stars. These were in turn children of even earlier stars, and so on. Generally, each new generation of stars has a bit more metal than the last. The very first stars, those born from the primordial hydrogen and helium of the cosmos, had almost no metal in them. We’ve never seen one of these primordial stars, but with the power of the Webb and a bit of luck, we might catch a glimpse of them soon.
In a recent study accepted to The Astrophysical Journal Letters, a team of researchers at the University of Nevada, Las Vegas (UNLV) investigated the potential for life on exoplanets orbiting M-dwarf stars, also known as red dwarfs, which are both smaller and cooler than our own Sun and is currently open for debate for their potential for life on their orbiting planetary bodies. The study examines how a lack of an asteroid belt might indicate a less likelihood for life on terrestrial worlds.
When we look at images of star birth regions, they look both placid and active at the same time. That’s nowhere more true than in a stellar nursery associated with a so-called “Herbig-Haro” object. A recent image from Hubble Space Telescope zeroed in on two called “HH 1” and “HH 2”. It looked at the turbulence associated with a nearby newborn star system.
What if you placed an Earth-sized planet in a close orbit around an M-dwarf star? It’s more than an academic question since M dwarfs are the most numerous stars we know. A group of astronomers studying the planet GJ 1252b found an answer and it’s not pretty.
Red supergiant stars are explosions waiting to happen. They are in the last stage of their life, red and swollen as they fuse heavier elements in a last effort to keep from collapsing. But eventually, gravity will win and the red supergiant core will collapse, triggering a supernova. We know it will happen, but until recently, we didn’t know when.
Back in August, an early release image from the James Webb Space Telescope revealed a bizarre sight: as many as 17 concentric rings encircling a binary star system, called Wolf-Rayet 140. Was it a spiral nebula, an alien megastructure or just an optical illusion?
The answer, revealed today, is dust. A new paper published in Nature Astronomy explains how stellar winds in this odd binary system blasts dust into near-perfect concentric circles every time the two stars come close to each other in their eccentric orbits.
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.