The Hubble Space Telescope is tracking down a suspected black hole that shredded a wayward star that came too close for comfort.
The famed space observatory made the find while hunting down the source of a powerful burst of X-rays caught in 2006 by two other cosmic telescopes: NASA’s Chandra X-ray Observatory and the European Space Agency’s X-ray Multi-Mirror Mission (XMM-Newton).
At the time, astronomers weren’t sure if the X-rays had come from inside or outside of the Milky Way galaxy, but new high-resolution photography by Hubble shows that the X-ray source (known as 3XMM J215022.4−055108) is located in a star cluster at the edge of another galaxy. That’s exactly where an intermediate-sized black hole (IMBH) may lurk — at least, according to theory.
This Hubble Space Telescope image shows the location of an intermediate-mass black hole named 3XMM J215022.4−055108 (in the white circle). Hubble’s high-resolution imagery revealed that the black hole resides inside a dense star cluster far beyond the Milky Way galaxy, in the outskirts of another galaxy pictured at the center of this image. (Image credit: NASA/ESA/D. Lin (University of New Hampshire))
The team’s work further suggests the star cluster may have been the core of a small dwarf galaxy disrupted long ago, when the dwarf galaxy strayed too close to the larger galaxy that currently hosts the star cluster. Gravitational interactions with the larger galaxy may have ripped the dwarf galaxy apart, leaving only a small cluster of stars in its wake. In much the same way, astronomers believe that the gravitational pull of the black hole inside this cluster shredded a star that got too close, thereby producing the X-ray flare detected in 2006.
If the X-rays indeed came from a black hole, astronomers suspect the object is about 50,000 times the mass of our sun. That’s a featherweight compared with the supermassive black hole that lies in the center of our Milky Way galaxy, which has a mass four million times greater than that of the sun.
“IMBHs have been particularly difficult to find because they are smaller and less active than supermassive black holes; they do not have readily available sources of fuel, nor as strong a gravitational pull to draw stars and other cosmic material which would produce telltale X-ray glows,” NASA officials said in a statement. “Astronomers essentially have to catch an IMBH red-handed in the act of gobbling up a star.”
An artist’s impression of an intermediate-mass black hole tearing apart a wayward star that passed too close. (Image credit: NASA/ESA/D. Player (STScI))
IMBHs are believed to be a “missing link” in our understanding of how black holes evolve. Astronomers have seen many examples of small black holes that are similar in size to a star, and other examples of much larger black holes that typically reside in the centers of galaxies.
But IMBHs remain difficult to confirm as astronomers struggle to understand how supermassive black holes got so darn big, compared to stellar-sized black holes. Hubble and other observatories have found other IMBH candidates in the past, but this newest observation is considered the strongest evidence yet for this class of black hole, according to NASA.
“Intermediate-mass black holes are very elusive objects, and so it is critical to carefully consider and rule out alternative explanations for each candidate. That is what Hubble has allowed us to do for our candidate,” Dacheng Lin, a research assistant professor at the University of New Hampshire and principal investigator of the new study, said in the statement.
One other theory for the X-rays was that a neutron star — the dense remnants of an exploded supernova star — may have been responsible. Based on the X-ray glow of the chewed-up star, however, astronomers calculated that the black hole’s mass was 50,000 solar masses, which is far more massive than a neutron star (typically about the size of a small city). The mass was calculated using both the X-ray luminosity — the inherent brightness of the X-rays — and the shape of the spectrum.
Hubble also helped track down another possible IMBH in 2009. The object, called HLX-1, was spotted on the edge of a galaxy known as ESO 243-49 — and also resides in a star cluster that could have been a dwarf galaxy in the ancient past. The X-rays spotted in the case of HLX-1, however, likely came from the accretion disk surrounding the black hole. The accretion disk is considered the point of no return for light or other objects to escape a black hole’s gravity.
“The main difference is that our object is tearing a star apart, providing strong evidence that it is a massive black hole, instead of a stellar-mass black hole as people often worry about for previous candidates including HLX-1,” Lin said.
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.
