Scientists have discovered an astronomical object that has never been observed before.
It is more massive than collapsed stars, known as “neutron stars”, but has less mass than black holes.
Such “black neutron stars” were not thought possible and will mean ideas for how neutron stars and black holes form will need to be rethought.
The discovery was made by an international team using gravitational wave detectors in the US and Italy.
Charlie Hoy, a PhD student from Cardiff University, UK, involved in the study, said the new discovery would transform our understanding.
“We can’t rule out any possibilities,” he told BBC News. “We don’t know what it is and this is why it is so exciting because it really does change our field.”
Mr Hoy is part of an international team working for the Ligo-Virgo Scientific Collaboration.
The international group, which has strong UK involvement backed by the Science and Technologies Facilities Council, has laser detectors several kilometres long that are able to detect minute ripples in space-time caused by the collision of massive objects in the Universe.
The collected data can be used to determine the mass of those objects involved.
Last August, the instruments detected the collision of a black hole 23 times the mass of our Sun with an object of 2.6 solar masses.
That makes the lighter object more massive than the heaviest type of dead star, or neutron star, previously observed – of just over two solar masses. But it was also lighter than the lightest black hole previously observed – of around five solar masses.
Astronomers have been searching for such objects in what they’ve come to call the “mass gap”.
Writing in the journal The Astrophysical Journal Letters, the research team believes that of all the possibilities, the object is most likely to be a light black hole, but they are not ruling out any other possibilities.
Gravitational waves are a prediction of the Theory of General Relativity
It took decades to develop the technology to directly detect them
They are ripples in the fabric of space-time generated by violent events
Accelerating masses will produce waves that propagate at the speed of light
Detectable sources include merging black holes and neutron stars
Ligo/Virgo fire lasers into long, L-shaped tunnels; the waves disturb the light
Detecting the waves opens up the Universe to completely new investigations
Having collided with the large black hole, the object no longer exists. However, there should be further opportunities to learn more about these mass-gap objects from future collisions, according to Prof Stephen Fairhurst, also at Cardiff.
“It is a challenge for us to determine what this is,” he told BBC News. “Is this the lightest black hole ever, or is it the heaviest neutron star ever?”
If it is a light black hole then there is no established theory for how such an object could develop. But Prof Fairhurst’s colleague, Prof Fabio Antonioni, has proposed that a solar system with three stars could lead to the formation of light black holes. His ideas are receiving increased attention following the new discovery.
If, however, this new class of object is a heavy neutron star then theories for how they form may also need to be revised, according to Prof Bernard Schutz of the Max Planck Institute for Gravitational Physics in Potsdam, Germany.
“We don’t know a lot about the nuclear physics of neutron stars. So, people who are looking at exotic equations that explain what goes on inside them might be thinking, ‘maybe this is evidence that we can get much heavier neutron stars’.”
Both black holes and neutron stars are thought to form when stars run out of fuel and die. If it is a very large star, it collapses to form a black hole, an object with such strong gravitational force that not even light can escape its grasp.
If the starting star is below a certain mass, one option is for it to collapse into a dense ball composed entirely of particles called neutrons, which are found inside the heart of atoms.
The material from which neutron stars are composed is so tightly packed that one teaspoonful would weigh 10 million tonnes.
A neutron star also has powerful gravity pulling it together, but a force between the neutrons, called the nuclear strong force, pushes the particles apart, counteracting the gravitational force.
Current theories suggest that the gravitational force would overcome the nuclear force if the neutron star were much larger than two solar masses – and cause it to collapse into a black hole.
According to Prof Nils Andersson of Southampton University, if the mystery object is a heavy neutron star then the theorists will have to rethink what goes on in these objects.
“Nuclear physics is not a precise science where we know everything,” he said.
“We don’t know how the nuclear strong force operates under the extreme conditions you need inside a neutron star. So, every single current theory we currently have of what goes on inside of one has some uncertainty.”
Prof Sheila Rowan, director of the University of Glasgow’s Institute for Gravitational Research (IGR), said the discovery challenges current theoretical models.
“More cosmic observations and research will need to be undertaken to establish whether this new object is indeed something that has never been observed before or whether it may instead be the lightest black hole ever detected.”
A laser is fed into the machine and its beam is split along two paths
The separate paths bounce back and forth between damped mirrors
Eventually, the two light parts are recombined and sent to a detector
Gravitational waves passing through the lab should disturb the set-up
Theory holds they should very subtly stretch and squeeze its space
This ought to show itself as a change in the lengths of the light arms
The photodetector captures this signal in the recombined beam
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
