A star exploding at the end of its life has rocked the cosmos like no other that humanity has ever seen.
In 2021, astronomers watched in astonishment as a supernova 2.2 billion light-years away named SN2021yfj bloomed, rich with silicon, sulfur, and argon – something never before seen in an exploding star.
In 2023, astronomers recorded one of the most extraordinary space explosions they had ever seen.
It took place some 750 million light-years away, flaring into the detectors of the Zwicky Transient Facility on 7 July. At first, it looked just like a normal supernova – the explosive death of a star – and astronomers named it SN 2023zkd.
A recent discovery by a team of astronomers centres on a galaxy cluster called CHIPS 1911+4455, located an incredible 6 billion light-years from Earth.
At its heart lies a supermassive black hole that has only recently ‘turned on’, just a thousand years ago. While that might sound like a long time, it’s merely a blink of an eye in astronomical terms.
Lead researcher Francesco Ubertosi from the University of Bologna describes the phenomenon as watching a sleeping giant wake up.
We live in an age of exoplanet discovery, and have discovered several thousand planets orbiting distant stars. These discoveries hold important lessons about planetary formation and solar system architecture. But we’re also discovering a growing number of rogue planets, also called free-floating planets. These planets aren’t gravitationally bound to any star. What can they teach us?
If detecting exoplanets was easy, then we should have a complete understanding of the planetary system around our nearest stellar neighbour, Alpha Centauri. But we don’t, because it’s not easy. Alpha Centauri is a triple star system about 4.25 light-years away. The primary star is called Alpha Centauri A, a Sun-like star, and it’s in a binary relationship with Alpha Centauri B, another Sun-like star. The third star is a red dwarf named Proxima Centauri, and it’s the closest one to us.
Around three decades ago, we weren’t certain that other stars had planets orbiting them. Scientists naturally thought there would be, but they had no evidence. Now, not only do we know of more than 6,000 confirmed exoplanets, but we can watch as baby planets take shape around distant stars.
When stars form, they’re surrounded by rotating disks of gas and dust called protoplanetary disks. Planets form in these disks, and in recent years, ALMA (Atacama Large Millimeter/submillimeter Array has examined many of these disks. It’s made headlines by finding telltale signs of planets forming, as they seem to clear orbital paths in the disks.
You’d think a star wouldn’t stand a chance against a supermassive black hole. But astronomers have spotted a star that apparently did battle with one of these behemoths, and later came back for another fight.
In 2022, astronomers spotted a bright flare at the center of a galaxy some 408 million light-years away. Labeled AT 2022dbl, it was what’s known as a tidal disruption event, where a star passes too close to a supermassive black hole, which rips it to shreds.
The day before my thesis examination, my friend and radio astronomer Joe Callingham showed me an image we’d been awaiting for five long years – an infrared photo of two dying stars we’d requested from the Very Large Telescope in Chile.
I gasped – the stars were wreathed in a huge spiral of dust, like a snake eating its own tail.