Gamma-ray bursts (GRBs) are one of the most mysterious transient phenomena facing astronomers today. These incredibly energetic bursts are the most powerful electromagnetic events observed since the Big Bang and can last from a few milliseconds to many hours. Whereas longer bursts are thought to occur during supernovae, when massive stars undergo gravitational collapse and shed their outer layer to become black holes, shorter events have also been recorded when massive binary objects (black holes and neutron stars) merge.
These bursts are characterized by an initial flash of gamma rays and a longer-lived “afterglow” typically emitted in X-ray, ultraviolet, radio, and other longer wavelengths. In the early-morning hours on October 14th, 2022, two independent teams of astronomers using the Gemini South telescope observed the aftermath of a GRB designated GRB221009A. Located 2.4 billion light-years away in the Sagitta constellation, this event was perhaps the closes and most powerful explosion ever recorded and was likely triggered by a supernova that gave birth to a black hole.
Longer-duration GRBs occur when massive stars go supernova, producing a remnant black hole and blowing off their outer layers. The force of this explosion creates powerful jets as ejected material is accelerated to nearly the speed of light, pushing through debris and emitting X-rays and gamma-rays as they reach further into space. If these jets travel in the general direction of Earth, astronomers will observe them as bright flashes of X-rays and gamma-rays. Using data from some of the most powerful telescopes on Earth and in space, astronomers were able to make unprecedented observations of a nearby GRB.
GRB221009A was first detected on the morning of October 9th, 2022, by X-ray and gamma-ray space telescopes – including NASA’s Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and the Wind spacecraft. Almost immediately after, observatories worldwide raced to conduct follow-up observations and determine what resulted. Using the Gemini South telescope (operated by NOIRLab), two independent teams made rapid Target of Opportunity (ToO) observations of the powerful event’s afterglow.
As Rastinejad explained in a recent NOIRLab’s press release, their combined datasets produced an image of what could be the brightest GRB ever observed:
“In our research group, we’ve been referring to this burst as the ‘BOAT,’ or Brightest Of All Time, because when you look at the thousands of bursts gamma-ray telescopes have been detecting since the 1990s, this one stands apart. Gemini’s sensitivity and diverse instrument suite will help us to observe GRB221009A’s optical counterparts to much later times than most ground-based telescopes can observe. This will help us understand what made this gamma-ray burst so uniquely bright and energetic.“
The speed with which the teams made their observations is a testament to the Gemini Observatory’s infrastructure and data-reduction software – including the Fast Initial Reduction Engine (FIRE) and Data Reduction for Astronomy from Gemini Observatory North and South (DRAGONS) platforms. Shortly after, the NASA Gamma-ray Coordinates Network began filling up with reports from observatories worldwide. Based on the available data, scientists believe that the GRB was the result of a collapse of a star many times the mass of our Sun that gave birth to a black hole.
Artistic representation of two merging neutron stars. Credit: Dana Berry, SkyWorks Digital, Inc.
What’s more, the data from this event may help resolve an ongoing mystery regarding GRBs. Whereas most gamma-ray bursts have been observed in distant galaxies, some appear as lonely flashes from intergalactic space. This has raised questions about the true origins and distances of GRBs, with many astronomers theorizing that certain short bursts originate in the intergalactic medium (IGM). However, these results suggest that short GRBs may have been more common in the past than expected.
The research teams came to this conclusion after consulting data on the 120 short GRBs observed by the two main instruments aboard NASA’s Neil Gehrels Swift Observatory – the Burst Alert Telescope (BAT) and the Swift X-ray Telescope, which detect bursts and examine the X-ray afterglow. They paired this with additional afterglow studies made with the Lowell Discovery Telescope (LDT), which found that 43 of the short GRBs were not associated with any known galaxy and appeared in the comparatively empty space between galaxies. As O’Connor explained in a University of Maryland news story:
“Many short GRBs are found in bright galaxies relatively close to us, but some of them appear to have no corresponding galactic home. By pinpointing where the short GRBs originate, we were able to comb through troves of data from observatories like the twin Gemini telescopes to find the faint glow of galaxies that were simply too distant to be recognized before.”
These findings could also have implications for our understanding of the early Universe. In recent years, astronomers have found evidence that precious metals like gold and platinum may have come from neutron star mergers that happened billions of years ago. If these events were more common in the past, it could mean that the Universe was seeded with precious metals earlier than expected. In the meantime, the energetic nature of this event makes it a once-in-a-lifetime opportunity for astronomers. As O’Conner explained:
“The exceptionally long GRB 221009A is the brightest GRB ever recorded and its afterglow is smashing all records at all wavelengths. Because this burst is so bright and also nearby, we think this is a once-in-a-century opportunity to address some of the most fundamental questions regarding these explosions, from the formation of black holes to tests of dark matter models.”
Artist’s impression of two neutron stars colliding, known as a “kilonova” event. Credits: Elizabeth Wheatley (STScI)
Because of its relative proximity to Earth, this event is also a unique opportunity to study the origin of the elements heavier than iron (which form in the interiors of stars) and whether they come from neutron-star mergers alone or collapsing stars as well. Last, but not least, this event also led to disturbances in the Earth’s ionosphere that affected long-wave radio transmissions and produced very high-energy (18 tera-electron-volt) photons detected by the Chinese Large High Altitude Air Shower Observatory.
How these photons survived the 2.4 billion-year journey to Earth is a mystery. Therefore, this data could reveal new insight into how the laws of physics behave in extreme circumstances and allow astrophysics to predict the effect that future GRBs could have on Earth.
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.
