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Astronomers find another strange fast radio burst from distant galaxy – CBC News

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Powerful bursts of radio waves emanating from a distant dwarf galaxy that were detected using a massive telescope in China are moving scientists closer to solving what one called a “cosmic mystery” that has lingered for years.

Since being discovered in 2007, astronomers have struggled to understand what causes phenomena called fast radio bursts involving pulses of radio-frequency electromagnetic radiation originating from places inside our Milky Way and other galaxies. Radio waves have the longest wavelengths in the electromagnetic spectrum.

Astronomers suspect that these bursts may be unleashed by certain extreme objects. These might include: a neutron star, the compact collapsed core of a massive star that exploded as a supernova at the end of its life cycle; a magnetar, a type of neutron star with an ultra-strong magnetic field; and a black hole messily eating a neighbouring star.

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Researchers on Wednesday said they have detected a fast radio burst, or FRB, originating from a dwarf galaxy located nearly three billion light-years from Earth. A light year is the distance light travels in a year — 9.5 trillion km. This galaxy’s collective star mass is roughly one-2,500th that of our Milky Way.

The FRB was first spotted in 2019 using the FAST telescope in China’s Guizhou province, the world’s largest single-dish radio telescope, which possesses a signal-receiving area equal to 30 football fields. It was studied further using the Very Large Array telescope in New Mexico.

An aerial view shows the Five-hundred-meter Aperture Spherical Telescope (FAST) in the remote Pingtang county in southwest China’s Guizhou province. (Liu Xu/Xinhua/Associated Press)

“We still call fast radio bursts a cosmic mystery and rightfully so,” said astrophysicist Di Li of the Chinese Academy of Sciences in Beijing, the FAST chief scientist and co-author of the research published in the journal Nature.

“Fast radio bursts are intense, brief flashes of radio light that are powerful enough to be seen from across the universe,” added Caltech astronomer and study co-author Casey Law. “The burst blinks on and off in about a millisecond, far faster than the blink of an eye. Some sources of FRBs have been found to emit multiple bursts in what look like storms of activity, but others have only been seen to burst once.”

Canadian connection

The newly described FRB is a repeating one that also features a persistent but weaker radio emission between bursts. In other words, it always remains “on.” Most of the roughly 500 known FRBs do not repeat. The new one closely resembles another discovered in 2015 — by Canadian Paul Scholz who was McGill PhD student at the time — that was the first FRB whose location was pinpointed.

Canada remains one of the major investigators of these mysterious signals. In 2017, the Canadian Hydrogen Intensity Mapping Experiment (CHIME), began operations in the mountains of B.C. at the Dominion Radio Astrophysical Observatory near Penticton. One of its goals is to detect FRBs, as well as monitor pulsars, measure the expansion of the universe and help detect gravitational waves

In its first year of operation, the telescope detected more than 500 FRBs.

WATCH | CHIME telescope unveiled in B.C.

New radio telescope unveiled in B.C.

5 years ago

Duration 2:04

Scientists hope CHIME, Canada’s largest radio telescope, will be a major step forward in uncovering the secrets of the universe

Li noted that numerous hypotheses have been offered to try to explain these bursts.

“The abundance of models reflects our lack of understanding of FRBs. Our work favours active repeaters being born out of an extreme explosive event such as a supernova. These active repeaters are also young, as they have to be seen not long after the birthing event,” Li said.

The astronomers suspect that the newly described FRB is a “newborn,” still enveloped by dense material blown into space by a supernova explosion that left behind a neutron star. They said repeating bursts may be a trait of younger FRBs, perhaps dissipating over time.

Discoveries like the newly described FRB may help scientists determine the cause of these radio bursts. Scientists previously were able to craft an explanation for the cause of another enigmatic phenomenon — hugely energetic explosions called gamma-ray bursts — as originating from the death of massive stars, merging neutron stars and magnetars.

“FRBs have rapidly risen to become a wonderful example of an astrophysical puzzle, just as gamma-ray bursts were a few decades ago,” Law said.

“We know more and more about the phenomenon, where the sources live, how often they burst, etc. However, we are still chasing for that golden measurement that will give us a definitive answer to what causes them.”

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Green comet making its closest approach to Earth in 50,000 years – Yahoo Movies Canada

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A rare green comet, that has not been seen for 50,000 years, is about to make its closest pass by Earth, becoming visible in a once-in-a-lifetime opportunity.

Called C/2022 E3 (ZTF), this celestial object hails from the Oort cloud at the outermost edge of the solar system.

Its green glow is a result of ultraviolet radiation from the sun lighting up the gases surrounding the comet’s surface.

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The icy ball orbits the sun once every 50,000 years, which means the last time it went past the planet was during the Stone Age – when Neanderthals roamed the Earth.

It is due to pass closest to the planet – still some 42 million kilometres away –  on Wednesday night, into the early hours of Thursday and in a very dark sky will appear as a faint smudge to those looking for it with the naked eye.

However, even if the moon is too bright for stargazers to spot the comet on Wednesday night, they might be able to catch a glimpse of it a week later when it passes Mars.

Professor Don Pollacco, from the department of physics at the University of Warwick, told the PA news agency: “Comet C/2022 E3 passes closest to Earth tonight, on 1 February.

“It has been christened the “Green Comet” as pictures show the head of the Comet to have a striking colour.

“We understand this as due to light emitted from carbon molecules ejected from the nucleus due to the increase in heat etc during its closest approach to the sun, which happened around 12 January.

“Some comets approach the sun much closer and are completely evaporated by the intense radiation.”

He added: “As the comet approaches Earth (it’s still 42 million km away, so no chance of a collision) it appears to move more quickly across the sky on a night-by-night basis.

“Tonight the comet is about halfway between the pole star and the bright star Capella, overhead about 11pm.

“However, the waxing moon will make the Comet much harder to spot. To see it you’ll need a clear sky, binoculars and a bit of luck.

“Alternately, if you wait a few days to around 10 February, the moon will be less bright and the comet will be clearer to see in the southern part of the sky, passing Mars.”

The Greenwich Royal Observatory says that from the northern hemisphere, the comet is already visible in the night sky using a telescope or some binoculars.

It adds: “Comet C/2022 E3 (ZTF) will be closest to Earth on February 1. This will also be the moment the comet appears at its brightest, and currently it is expected to reach a brightness magnitude of +6. That would mean it would be visible to the naked eye.

“It’s worth noting, however, that comets can be unpredictable, and it’s hard to say with accuracy how bright the comet will be or what it will look like ahead of time.

“The comet looks like a fuzzy green ball or smudge in the sky. This green glow is a result of UV radiation from the sun lighting up the gases streaming off of the comet’s surface.”

Advising on where the comet can be seen in the night sky, the Observatory says: “When it passes near Earth in February, the green comet will be in the constellation of Camelopardalis.

“After its closest approach, the green comet will move through Auriga and end up in Taurus mid-February.

“The comet will dim over the month as it moves away from us, and the time that it will be up in the sky during the night will get shorter and shorter.”

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New AI algorithm helps find 8 radio signals from space

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A new artificial intelligence algorithm created by a Toronto student is helping researchers search the stars for signs of life.

Peter Xiangyuan Ma, a University of Toronto undergraduate student and researcher, said he started working on the algorithm while he was in Grade 12 during the pandemic.

“I was just looking for projects and I was interested in astronomy,” he told CTV News Toronto.

The idea was to help distinguish between technological radio signals created by human technologies and signals that were potentially coming from other forms of life in space.

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“What we’re looking for is signs of technology that signifies if the sender is intelligent or not. And so unsurprised to us, we keep on finding ourselves,” Ma explained. “We don’t want to be looking at our own noisy signals.”

Using this algorithm, Ma said researchers were able to discover eight new radio signals being emitted from five different stars about 30 to 90 light years away from the Earth.

These signals, Ma said, would disappear when researchers looked away from it, which rules out, for the most part, interference from a signal originating from Earth. When they returned to the area, the signal was still there.

“We’re all very suspicious and scratching our heads,” he said. “We proved that we found things that we wanted to find … now, what do we do with all these? That’s another separate issue.”

Steve Croft, Project Scientist for Breakthrough Listen on the Green Bank Telescope, the institute whose open source data was the inspiration for Ma’s algorithm, said that finding radio signals in space is like trying to find a needle in a haystack.

“You’ve got to recognize the haystack itself and make sure that you don’t throw the needle away as you’re looking at the individual pieces of hay,” Croft, who collaborated on Ma’s research, told CTV News Toronto.

Croft said algorithms being used to discover these signals have to account for multiple characteristics, including the position they are coming from in the sky and whether or not the transmission changes over time, which could indicate if it’s coming from a rotating planet or star.

“The algorithm that Peter developed has enabled us to do this more efficiently,” he said.

The challenge, Croft says, is recognizing that false positives may exist despite a signal meeting this criteria. What could be signs of extraterrestrial life may also just be a “weirdly shaped bit of a haystack,” he added.

“And so that’s why we have to go back and look again and see if the signal still there. And with these particular examples that Peter found with his algorithm, the signal was not there when we pointed the telescope back again. And so we sort of can’t say one way or another, is this genuine?”

Researchers have been searching the sky for technologically-generated signals since the 1960s, searching thousands of stars and galaxies for signs of intelligent life. The process is called “SETI,” or “the Search for Extraterrestrial Intelligence.”

But interference from our own radio signals has always proven to be a challenge. Croft says most pieces of technology have some kind of Bluetooth or wireless wave element that creates static, resulting in larger amounts of data needed to be collected.

“That’s a challenge but also computing provides the solution,” he said.

“So the computing and particularly the machine-learning algorithms gives us the power to search through this big haystack, looking for the needle of an interesting signal.”

Ma said that while we may not have found a “technosignal” just yet, we shouldn’t give up. The next step would be to employ multiple kinds of search algorithms to find more and more signals to study.

Peter Ma

While the “dream” is to find evidence of life, Ma says he is more focused on the scientific efforts of actively looking for it.

This sentiment is echoed by Croft, who said he is most fascinating in working towards answering the question of whether humans are alone in this universe.

“I don’t show up to work every day, thinking I’m going to find aliens, but I do show up for work. So you know, I’ve got sort of some optimism.”

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How to spot the green comet in Manitoba

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Space enthusiasts in the province will get the chance to potentially see a rare green comet over the next couple of days.

The comet was discovered by astronomers in southern California last year and it was determined the last time it passed Earth was around 50,000 years ago.

Mike Jensen, the planetarium and science gallery program supervisor at the Manitoba Museum, said the time between appearances and the colour of the comet makes this unique compared to others.

“The last time it would have appeared anywhere within the region of visibility to Earth, we’re talking primitive humans walking the Earth,” said Jensen. “And then yes, its colour. Most people associate comets, they’re often referred to as ghosts of the night sky because they often have a bit of a whitish-blue appearance. This one’s got a bit of green to it. Comets are all made up of different types of material, this just happens to have a bit more of some carbon elements in it.”

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Jensen notes the green tint on the comet will be subtle, comparing it to the subtle red that surrounds Mars in the night sky.

Wednesday and Thursday are the best days to see the comet as Jensen said that’s when it will be closest to Earth – 42 million kilometres away.

“That proximity to us means it does get to its best visibility for us. The added advantage is it’s also appearing sort of high up in the northern sky, which puts it amongst the circumpolar stars of our night sky. In other words, the stars that are circling around the North Star.”

Now, just because the comet is close enough to be visible doesn’t mean it will be the easiest to see in the night sky according to Jensen. He said there are a few factors that play into having a successful sighting.

First, he suggests getting out of the city and away from the lights, noting, the darker it is, the better. If people head outside city limits, Jensen recommends people dress warmly, saying comet watching in the winter is not for the “faint of heart.”

Secondly, he said even though it might be possible to see the comet with the naked eye, he still suggests bringing binoculars to improve people’s chances. He also recommends checking star maps before leaving to get the most accurate location of where the comet may be.

Lastly, even if all of that is achieved, Jensen notes people will have to battle with the light of the moon, as it is close to a full moon.

“I’m not trying to dissuade anybody from going out to see it, but certainly, there’s going to be some hurdles to overcome in order to be able to spot it on your own.”

If people don’t want to go outside to see it, he said there are plenty of resources online to find digital views.

 – With files from CTV News’ Michael Lee

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