In this illustration of an ultra-luminous X-ray source, two rivers of hot gas are pulled onto the surface of a neutron star. Strong magnetic fields, shown in green, may change the interaction of matter and light near neutron stars’ surface, increasing how bright they can become. Credit: NASA/JPL-Caltech
These objects are more than 100 times brighter than they should be. Observations by <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
NASA
Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is "To discover and expand knowledge for the benefit of humanity." Its core values are "safety, integrity, teamwork, excellence, and inclusion." NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.
NuSTAR
NuSTAR, or Nuclear Spectroscopic Telescope Array, is a space-based X-ray telescope launched in 2012 and operated by the California Institute of Technology in collaboration with NASA and other international partners. NuSTAR has the unique ability to focus high-energy X-rays with very high resolution, allowing it to study some of the most extreme phenomena in the universe, such as black holes, supernovae, and neutron stars. Its instruments consist of telescopes sensitive to X-rays with energies ranging from 3 to 79 keV, making it one of the most sensitive X-ray telescopes ever built.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>NuSTAR X-ray telescope support a possible solution to this puzzle.
Ultra-luminous X-ray sources (ULXs) produce about 10 million times more energy than the Sun, regularly exceeding the Eddington limit by 100 to 500 times. This has left scientists puzzled as to how these cosmic objects can be so bright. A recent study published in The <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
Astrophysical Journal
The Astrophysical Journal (ApJ) is a peer-reviewed scientific journal that focuses on the publication of original research on all aspects of astronomy and astrophysics. It is one of the most prestigious journals in the field, and is published by the American Astronomical Society (AAS). The journal publishes articles on a wide range of topics, including the structure, dynamics, and evolution of the universe; the properties of stars, planets, and galaxies; and the nature of dark matter, dark energy, and the early universe.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>Astrophysical Journal utilized NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) to measure a ULX for the first time. Findings confirm that ULXs do indeed break the Eddington limit, potentially due to their strong magnetic fields. An alternative hypothesis suggests that the strong magnetic fields of ULXs distort atoms into elongated shapes, reducing the ability of photons to push atoms away and ultimately increasing an object’s maximum possible brightness.
Exotic cosmic objects known as ultra-luminous X-ray sources produce about 10 million times more energy than the Sun. They’re so radiant, in fact, that they appear to surpass a physical boundary called the Eddington limit, which puts a cap on how bright an object can be based on its mass. Ultra-luminous X-ray sources (ULXs, for short) regularly exceed this limit by 100 to 500 times, leaving scientists puzzled.
In a recent study published in The Astrophysical Journal, researchers report a first-of-its-kind measurement of a ULX taken with NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR). The finding confirms that these light emitters are indeed as bright as they seem and that they break the Eddington limit. A hypothesis suggests this limit-breaking brightness is due to the ULX’s strong magnetic fields. But scientists can test this idea only through observations: Up to billions of times more powerful than the strongest magnets ever made on Earth, ULX magnetic fields can’t be reproduced in a lab.
Illustration of the NuSTAR spacecraft, which has a 30-foot (10 meter) mast that separates the optics modules (right) from the detectors in the focal plane (left). This separation is necessary for the method used to detect X-rays. Credit: NASA/JPL-Caltech
Breaking the Limit
Particles of light, called photons, exert a small push on objects they encounter. If a cosmic object like a ULX emits enough light per square foot, the outward push of photons can overwhelm the inward pull of the object’s gravity. When this happens, an object has reached the Eddington limit, and the light from the object will theoretically push away any gas or other material falling toward it.
That switch – when light overwhelms gravity – is significant, because material falling onto a ULX is the source of its brightness. This is something scientists frequently observe in black holes: When their strong gravity pulls in stray gas and dust, those materials can heat up and radiate light. Scientists used to think ULXs must be black holes surrounded by bright coffers of gas. But in 2014, NuSTAR data revealed that a ULX by the name of M82 X-2 is actually a less-massive object called a neutron star. Like black holes, neutron stars form when a star dies and collapses, packing more than the mass of our Sun into an area not much bigger than a mid-size city.
This incredible density also creates a gravitational pull at the <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
neutron star
A neutron star is the collapsed core of a large (between 10 and 29 solar masses) star. Neutron stars are the smallest and densest stars known to exist. Though neutron stars typically have a radius on the order of just 10 – 20 kilometers (6 – 12 miles), they can have masses of about 1.3 – 2.5 that of the Sun.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>neutron star’s surface about 100 trillion times stronger than the gravitational pull on Earth’s surface. Gas and other material dragged in by that gravity accelerate to millions of miles per hour, releasing tremendous energy when they hit the neutron star’s surface. (A marshmallow dropped on the surface of a neutron star would hit it with the energy of a thousand hydrogen bombs.) This produces the high-energy X-ray light NuSTAR detects.
The recent study targeted the same ULX at the heart of the 2014 discovery and found that, like a cosmic parasite, M82 X-2 is stealing about 9 billion trillion tons of material per year from a neighboring star, or about 1 1/2 times the mass of Earth. Knowing the amount of material hitting the neutron star’s surface, scientists can estimate how bright the ULX should be, and their calculations match independent measurements of its brightness. The work confirmed M82 X-2 exceeds the Eddington limit.
No Illusions
If scientists can confirm of the brightness of more ULXs, they may put to bed a lingering hypothesis that would explain the apparent brightness of these objects without ULXs having to exceed the Eddington limit. That hypothesis, based on observations of other cosmic objects, posits that strong winds form a hollow cone around the light source, concentrating most of the emission in one direction. If pointed directly at Earth, the cone could create a sort of optical illusion, making it falsely appear as though the ULX were exceeding the brightness limit.
Even if that’s the case for some ULXs, an alternative hypothesis supported by the new study suggests that strong magnetic fields distort the roughly spherical atoms into elongated, stringy shapes. This would reduce the photons’ ability to push atoms away, ultimately increasing an object’s maximum possible brightness.
“These observations let us see the effects of these incredibly strong magnetic fields that we could never reproduce on Earth with current technology,” said Matteo Bachetti, an astrophysicist with the National Institute of Astrophysics’ Cagliari Observatory in Italy and lead author on the recent study. “This is the beauty of astronomy. Observing the sky, we expand our ability to investigate how the universe works. On the other hand, we cannot really set up experiments to get quick answers; we have to wait for the universe to show us its secrets.”
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center that was established in 1936. It is owned by NASA and managed by the California Institute of Technology (Caltech). The laboratory’s primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network. JPL implements programs in planetary exploration, Earth science, space-based astronomy and technology development, while applying its capabilities to technical and scientific problems of national significance.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>JPL) in Southern California for the agency’s Science Mission Directorate in Washington, NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp. in Dulles, Virginia. NuSTAR’s mission operations center is at the <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
University of California, Berkeley
Located in Berkeley, California and founded in 1868, University of California, Berkeley is a public research university that also goes by UC Berkeley, Berkeley, California, or Cal. It maintains close relationships with three DOE National Laboratories: Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>University of California, Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center at NASA’s Goddard Space Flight Center. ASI provides the mission’s ground station and a mirror data archive. Caltech manages JPL for NASA.
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.
