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Astronomical News

‘Puzzling’ discovery spotted in new images from NASA mission’s asteroid flyby​


https://www.cnn.com/2023/11/08/world/nasa-lucy-mission-dinkinesh-contact-binary-scn/index.html

Dinkinesh, a small asteroid that NASA’s Lucy mission visited last week, continues to surprise.

Lucy swung by the space rock, located in the main asteroid belt between Mars and Jupiter, on November 1 as part of a test of the spacecraft’s equipment before tackling the mission’s primary goal: surveying the swarms of Trojan asteroids around Jupiter. The flyby of Dinkinesh, which means “marvelous” in the Amharic language of Ethiopia, wasn’t even added to Lucy’s itinerary until January.

But the first views captured by Lucy’s instruments showed there was more to the shadowy asteroid than expected. At first, images suggested that the space rock was part of a binary pair, with a smaller asteroid orbiting Dinkinesh.

However, additional images taken by the spacecraft just after the flyby’s closest approach have now revealed that the smaller asteroid is actually a contact binary — two smaller space rocks that touch each other.
 

‘What the heck is going on?’ Extremely high-energy particle detected falling to Earth​

Named Amaterasu, after the sun goddess in Japanese mythology, it is one of the highest-energy cosmic rays ever detected, according to the scientists.

Its origins remain unknown but experts believe only the most powerful of celestial events – much bigger than a star explosion – can produce them.

John Matthews, a research professor at the University of Utah in the US, said: “Things that people think of as energetic, like supernova, are nowhere near energetic enough for this. You need huge amounts of energy, really high magnetic fields, to confine the particle while it gets accelerated.”
The Amaterasu particle has an energy exceeding 240 exa-electron volts (EeV), which is millions of times more than what particles achieve in the Large Hadron Collider, the most powerful accelerator ever built.

It comes only second to the Oh-My-God particle, another ultra-high-energy cosmic ray, which was detected in 1991 and possessed 320 EeV of energy.

Toshihiro Fujii, an associate professor at Osaka Metropolitan University in Japan, said: “When I first discovered this ultra-high-energy cosmic ray, I thought there must have been a mistake, as it showed an energy level unprecedented in the last three decades.”

When ultra-high-energy cosmic rays hit Earth’s atmosphere, they initiate a cascade of secondary particles and electromagnetic radiation in what is known as an extensive air shower.
Click to expand...

Some charged particles in the air shower travel faster than the speed of light, producing a type of electromagnetic radiation that can be detected by specialised instruments.

This mysterious event appears to have emerged from the Local Void, an empty area of space bordering the Milky Way galaxy.
Matthews said: “The particles are so high energy, they shouldn’t be affected by galactic and extra-galactic magnetic fields. You should be able to point to where they come from in the sky. But in the case of the Oh-My-God particle and this new particle, you trace its trajectory to its source and there’s nothing high energy enough to have produced it. That’s the mystery of this – what the heck is going on?”
Click to expand...
 
hunck said:

‘What the heck is going on?’ Extremely high-energy particle detected falling to Earth​

Named Amaterasu, after the sun goddess in Japanese mythology, it is one of the highest-energy cosmic rays ever detected, according to the scientists.

Its origins remain unknown but experts believe only the most powerful of celestial events – much bigger than a star explosion – can produce them.

John Matthews, a research professor at the University of Utah in the US, said: “Things that people think of as energetic, like supernova, are nowhere near energetic enough for this. You need huge amounts of energy, really high magnetic fields, to confine the particle while it gets accelerated.”


Some charged particles in the air shower travel faster than the speed of light, producing a type of electromagnetic radiation that can be detected by specialised instruments.
Click to expand...
Could it possibly have been circularly accelerating out there, gaining more energy on it's way, then somehow managed to spin off in this direction after an energy source built up to such high degree that it 'ran away' on it's own powered-up trajectory?
 
Further clouding of the issue.

A large international team of astronomers and astrophysicists has found evidence showing that the Small Magellanic Cloud is not a single galaxy—it is actually two, one behind the other. The group has written a paper describing their work and posted it to the arXiv preprint server.

The Magellanic Clouds have for many years been known as two irregular dwarf galaxies that can be seen as appearing very close to one another in the southern celestial hemisphere. They have also been named individually as the Large and Small Magellanic Clouds, based on their sizes. In the late 1980s, some evidence arose suggesting that the Small Magellanic Cloud (SMC) was not one, but two dwarf galaxies. In this new effort, the researchers have found more evidence, showing that the SMC is indeed two small dwarf galaxies.

To learn more about the SMC, the research team first studied data from the ESA's space-based Gaia observatory that allowed them to make estimations of the average velocity of the stars in various parts of the SMC. Next, they studied data from the Galactic Australian Square Kilometer Array Pathfinder, a radio telescope array in Western Australia, which allowed them to learn more about the Interstellar Medium in both the SMC and LMC. They also analyzed data from the APOGEE survey, which came courtesy of duel 300-fiber spectrographs at the Sloan Foundation Telescope and the NMSU Telescope, both of which are located at the Apache Point Observatory in New Mexico. ...

https://phys.org/news/2023-12-small-magellanic-cloud-smaller-galaxies.html
 
Swarming Proxima Centauri

Humans have dreamed about traveling to other star systems and setting foot on alien worlds for generations. To put it mildly, interstellar exploration is a very daunting task.

As Universe Today explored in a previous post, it would take between 19,000 and 81,000 years for a spacecraft to reach Proxima Centauri using conventional propulsion (or those that are feasible using current technology). On top of that, there are numerous risks when traveling through the interstellar medium (ISM), not all of which are well-understood.

Under the circumstances, gram-scale spacecraft that rely on directed-energy propulsion (AKA lasers) appear to be the only viable option for reaching neighboring stars in this century.

Proposed concepts include the Swarming Proxima Centauri, a collaborative effort between Space Initiatives Inc. and the Initiative for Interstellar Studies (i4is) led by Space Initiative's chief scientist Marshall Eubanks. The concept was recently selected for Phase I development as part of this year's NASA Innovative Advanced Concepts (NIAC) program.

According to Eubanks, traveling through interstellar space is a question of distance, energy, and speed. At a distance of 4.25 light-years (40 trillion km; 25 trillion mi) from the Solar System, even Proxima Centauri is unfathomably far away.

To put it in perspective, the record for the farthest distance ever traveled by a spacecraft goes to the Voyager 1 space probe, which is currently more than 24 billion km (15 billion miles) from Earth. Using conventional methods, the probe accomplished a maximum speed of 61,500 km/h (38,215 mph) and has been traveling for more than 46 years straight.

https://www.sciencealert.com/nasa-s...roxima-centauri-with-thousands-of-tiny-probes
 

Huge ring of galaxies challenges thinking on cosmos​

_132281250_figure_2.jpg.webp


Scientists at the University of Central Lancashire have discovered a gigantic, ring-shaped structure in space.
It is 1.3bn light-years in diameter and appears to be roughly 15 times the size of the Moon in the night sky as seen from Earth.
Named the Big Ring by the astronomers, it is made up of galaxies and galaxy clusters.
They say that it is so big it challenges our understanding of the universe.
It cannot be seen with the naked eye. It is really distant and identifying all the galaxies that make up the bigger structure has taken a lot of time and computing power.
Such large structures should not exist according to one of the guiding principles of astronomy, called the cosmological principle. This states that all matter is spread smoothly across the Universe.

Although stars, planets and galaxies are huge clumps of matter in our eyes, in the context of the size of the universe they are insignificant - and the theory is that much bigger patches of matter should not form.
The Big Ring is by no means the first likely violation of the cosmological principle and so suggests that there is another, yet to be discovered, factor at play.
According to Dr Robert Massey, deputy director of the Royal Astronomical Society, the evidence for a rethink of what has been a central plank of astronomy is growing.
"This is the seventh large structure discovered in the universe that contradicts the idea that the cosmos is smooth on the largest scales. If these structures are real, then it's definitely food for thought for cosmologists and the accepted thinking on how the universe has evolved over time," he said.


Full story on BBC News
 
Ascalon said:

Huge ring of galaxies challenges thinking on cosmos​

_132281250_figure_2.jpg.webp


Scientists at the University of Central Lancashire have discovered a gigantic, ring-shaped structure in space.
It is 1.3bn light-years in diameter and appears to be roughly 15 times the size of the Moon in the night sky as seen from Earth.
Named the Big Ring by the astronomers, it is made up of galaxies and galaxy clusters.
They say that it is so big it challenges our understanding of the universe.
It cannot be seen with the naked eye. It is really distant and identifying all the galaxies that make up the bigger structure has taken a lot of time and computing power.
Such large structures should not exist according to one of the guiding principles of astronomy, called the cosmological principle. This states that all matter is spread smoothly across the Universe.

Although stars, planets and galaxies are huge clumps of matter in our eyes, in the context of the size of the universe they are insignificant - and the theory is that much bigger patches of matter should not form.
The Big Ring is by no means the first likely violation of the cosmological principle and so suggests that there is another, yet to be discovered, factor at play.
According to Dr Robert Massey, deputy director of the Royal Astronomical Society, the evidence for a rethink of what has been a central plank of astronomy is growing.
"This is the seventh large structure discovered in the universe that contradicts the idea that the cosmos is smooth on the largest scales. If these structures are real, then it's definitely food for thought for cosmologists and the accepted thinking on how the universe has evolved over time," he said.


Full story on BBC News
Click to expand...
As it seems to be an enormous Giant Ring Cluster, maybe it's a sign of a marriage made in heaven? :bthumbup:
 

Milky Way: Manchester astronomers find mysterious object​

A new object in the Milky Way that is heavier than the heaviest neutron stars known to scientists, and yet lighter than the lightest known black holes, has been found by astronomers.
Researchers in Manchester and Germany found it orbiting a millisecond pulsar 40,000 light years away.
Millisecond pulsars spin very rapidly - hundreds of times per second.

Researchers from the University of Manchester and the Max Planck Institute for Radio Astronomy in Munich, believe it could be the first discovery of a radio pulsar-black hole binary - a pairing that could allow new tests of Einstein's general relativity and open doors to the study of black holes.

The discovery of the object was made while observing a large cluster of stars known as NGC 1851, located in the southern constellation of Columba, using the MeerKAT telescope in South Africa.

Astronomers say it is so crowded that the stars can interact with each other, disrupting orbits and in the most extreme cases colliding.

They believe a collision between two neutron stars may have created the massive object that now orbits the radio pulsar.

While the team cannot conclusively say whether they have discovered the most massive neutron star to date, the lightest black hole or even some new exotic star variant, they have uncovered something that will help to probe the properties of matter under the most extreme conditions in the universe.
Click to expand...
 
From the Daily Grail.

Astronomers have discovered a ring of planetary debris that appears to contain 65 moon-sized structures orbiting close to a white dwarf star. The curious part: each structure passes in front of the star on a regular basis, precisely every 23.1 minutes – a mystery, researchers say, they “cannot currently explain”.

https://www.dailygrail.com/2022/02/...ts-that-transit-precisely-23-1-minutes-apart/
 
Unfortunately they are described as irregular and dusty, meaning likely not artificial. Still interesting, as its evidence there must be a planet gravitationally shepherding them.
 
Puts me in mind of that comet breaking up and smacking into Jupiter with a regular pattern 30 odd years ago.
 
This could almost go into the ‘Expressing Measurements Via Analogies & Comparisons’ thread, but it’s basically astronomy.

A group of astronomers at the University of Western Ontario is now claiming that it is unlikely that there could be life on Saturn’s moon Titan. This is despite Titan being previously regarded as a top candidate. Their reasoning: comets would only puncture the ice crust often enough to “only at most transfer an elephant-mass equivalent of organic molecules (around 7,500 kilograms of glycine) a year into the potential sanctuary of the moon's ocean.”

And they think one elephant per year isn’t enough.

https://www.sciencealert.com/new-discovery-crushes-hopes-of-finding-alien-life-on-titan
 
Salmonellus said:
This could almost go into the ‘Expressing Measurements Via Analogies & Comparisons’ thread, but it’s basically astronomy.

A group of astronomers at the University of Western Ontario is now claiming that it is unlikely that there could be life on Saturn’s moon Titan. This is despite Titan being previously regarded as a top candidate. Their reasoning: comets would only puncture the ice crust often enough to “only at most transfer an elephant-mass equivalent of organic molecules (around 7,500 kilograms of glycine) a year into the potential sanctuary of the moon's ocean.”

And they think one elephant per year isn’t enough.

https://www.sciencealert.com/new-discovery-crushes-hopes-of-finding-alien-life-on-titan
Click to expand...
Depends on the size of the elephant....

Fifth-Elephant.jpg
 
Dark energy and dark matter may no longer be needed, according to a wobbly spacetime theory.

Controversial new theory of gravity rules out need for dark matter​

Exclusive: Paper by UCL professor says ‘wobbly’ space-time could instead explain expansion of universe and galactic rotation

From the Guardian.
 
Ascalon said:
Dark energy and dark matter may no longer be needed, according to a wobbly spacetime theory.

Controversial new theory of gravity rules out need for dark matter​

Exclusive: Paper by UCL professor says ‘wobbly’ space-time could instead explain expansion of universe and galactic rotation

From the Guardian.
Click to expand...
Ah! "Wobbly" space time not "Timey wimey." :)
 
Recurring Nova could be visible to naked eye this year

Sometime between now and September, a ’new’ star will appear in the sky – but only for a week.

3,000 light-years away, the star system T Coronae Borealis, or T Cr B, is about to explode. When it does, it will become visible to the naked eye here on Earth.

T Cr B last exploded in 1946, meaning some who saw it then could witness it again now – and many more will hopefully be around when it explodes again in another 80 or so years.

Astronomers predict that when it does erupt, it may be as bright as the North Star, Polaris.
As its brightness peaks, it should be visible to the naked eye for several days, and just over a week if you use binoculars before it dims again.

This recurring nova is one of five in our galaxy, and forms when a white dwarf and a red giant are close enough that when the red giant becomes unstable from increasing temperature and pressure, it ejects its outer layers, which the white dwarf collects onto its surface.

The matter heats up until it reaches a certain point, when a nuclear reaction and sets up a massive almost apocalyptic blast.

This doesn’t destroy the star like a supernova would, however, and after the nova cools down, the cycle begins again as the white dwarf gears up towards another explosion.

Historical reports show the nova was spotted in 1946, but it was first ‘seen ‘discovered’ in 1866 by Irish astronomer John Birmingham. However, reports also mention seeing the nova in 1787 and 1217.

Observations of T Cr B show that the nova acted erratically in the lead-up to its eruption, and its activity over the past decade suggests its gearing up for an explosion.
Click to expand...
 

Study: Conflicting values for Hubble Constant not due to measurement error​


/the conflict will potentially lead to new theories of the universe.

https://arstechnica.com/science/202...firms-hubbles-value-for-expansion-of-universe

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"We've measured it using information in the cosmic microwave background and gotten one value," Ars Science Editor John Timmer wrote. "And we've measured it using the apparent distance to objects in the present-day Universe and gotten a value that differs by about 10 percent. As far as anyone can tell, there's nothing wrong with either measurement, and there's no obvious way to get them to agree." One hypothesis is that the early Universe briefly experienced some kind of "kick" from repulsive gravity (akin to the notion of dark energy) that then mysteriously turned off and vanished. But it remains a speculative idea, albeit a potentially exciting one for physicists.

This latest measurement builds on last year's confirmation based on Webb data that Hubble's measurements of the expansion rate were accurate, at least for the first few "rungs" of the "cosmic distance ladder." But there was still the possibility of as-yet-undetected errors that might increase the deeper (and hence further back in time) one looked into the Universe, particularly for brightness measurements of more distant stars.

So a new team made additional observations of Cepheid variable stars—a total of 1,000 in five host galaxies as far out as 130 million light-years—and correlated them with the Hubble data. The Webb telescope is able to see past the interstellar dust that has made Hubble's own images of those stars more blurry and overlapping, so astronomers could more easily distinguish between individual stars.

The results further confirmed the accuracy of the Hubble data. “We’ve now spanned the whole range of what Hubble observed, and we can rule out a measurement error as the cause of the Hubble Tension with very high confidence," said co-author and team leader Adam Riess, a physicist at Johns Hopkins University. "Combining Webb and Hubble gives us the best of both worlds. We find that the Hubble measurements remain reliable as we climb farther along the cosmic distance ladder. With measurement errors negated, what remains is the real and exciting possibility that we have misunderstood the Universe.”"
 
According to Livescience.com, shocking our universe is not expanding evenly is this is now called Hubble Tension.

These measurements were confirmed by Hubble Telescope over the past few of years.

So much for the evenly spreading big bang.
 

Explosive star event will create once-in-a-lifetime sight in the sky. Here’s how to see it​


https://www.cnn.com/2024/03/19/world/t-coronae-borealis-nova-new-star-scn/index.html
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T Coronae Borealis last experienced an explosive outburst in 1946, and astronomers are keeping a watchful eye on the star system once more.

“Most novae happen unexpectedly, without warning,” said William J. Cooke, NASA Meteoroid Environments Office lead, in an email. “However, T Coronae Borealis is one of 10 recurring novae in the galaxy. We know from the last eruption back in 1946 that the star will get dimmer for just over a year before rapidly increasing in brightness. T Coronae Borealis began to dim in March of last year, so some researchers are expecting it to go nova between now and September. But the uncertainty as to when this will happen is several months — can’t do better than that with what we know now.”

The star system, located 3,000 light-years from Earth and typically too dim to be seen with the naked eye, is expected to reach a level of brightness similar to that of Polaris, or the North Star.

Once the nova peaks in brightness, it will be as if a new star has appeared — one that’s visible for a few days without any equipment and a little over a week with binoculars before it dims and disappears from sight for another 80 years or so.

The nova will appear in a small arc between the Boötes and Hercules constellations, and will be visible from the Northern Hemisphere.
 
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