A new fast radio burst (FRB) appears like clockwork, seeming to follow a mathematical pattern, says Kiyoshi Masui, assistant professor of physics in MIT’s Kavli Institute for Astrophysics and Space Research about a 16-day pattern of fast radio bursts reoccurring consistently over 500 days of observations from an unknown source outside our galaxy, 500 million light years away.
“It’s the most definitive pattern we’ve seen from one of these sources. And it’s a big clue that we can use to start hunting down the physics of what’s causing these bright flashes, which nobody really understands. These periodic bursts are something that we’ve never seen before, and it’s a new phenomenon in astrophysics,” Masui says.
The first FRB, the so-called Lorimer Burst (FRB 010724) was detected only a decade ago, leading some astronomers to speculate that they may be signatures of distant technology. Harvard’s Avi Loeb suggested in a 2017 paper that we could conceivably be dealing with an engineering phenomenon rather than a natural one.
This new source of curious, repeating rhythm of fast radio waves emanating FRB 180916.J0158+65, is the first to produce a periodic, or cyclical pattern beginning with a noisy, four-day window, during which the source emits random bursts, followed by a 12-day period of radio silence.
Fast radio bursts, or FRBs, are short, intense flashes of radio waves that are thought to be the product of small, distant, extremely dense objects, though exactly what those objects might be is a longstanding mystery in astrophysics. FRBs typically last a few milliseconds, during which time they can outshine entire galaxies.
FRBs Detected in Past Were One-Offs
Since the first FRB was observed in 2007, astronomers have cataloged over 100 fast radio bursts from distant sources scattered across the universe, outside our own galaxy. For the most part, these detections were one-offs, flashing briefly before disappearing entirely. In a handful of instances, astronomers observed fast radio bursts multiple times from the same source, though with no discernible pattern.
Masui is a member of the CHIME/FRB collaboration, a group of more than 50 scientists led by the University of British Columbia, McGill University, University of Toronto, and the National Research Council of Canada, that operates and analyzes the data from the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, a radio telescope in British Columbia that was the first to pick up signals of the new periodic FRB source. The CHIME/FRB Collaboration has published the details of the new observation today in the journal Nature.
In 2017, CHIME was erected at the Dominion Radio Astrophysical Observatory in British Columbia, where it quickly began detecting fast radio bursts from galaxies across the universe, billions of light years from Earth.
CHIME consists of four large antennas, each about the size and shape of a snowboarding half-pipe, and is designed with no moving parts. Rather than swiveling to focus on different parts of the sky, CHIME stares fixedly at the entire sky, using digital signal processing to pinpoint the region of space where incoming radio waves are originating.
38 FRBs from a Single Source
From September 2018 to February 2020, CHIME picked out 38 fast radio bursts from a single source, FRB 180916.J0158+65, which the astronomers traced to a star-churning region on the outskirts of a massive spiral galaxy, 500 million light years from Earth. The source is the most active FRB source that CHIME has yet detected, and until recently it was the closest FRB source to Earth.
As the researchers plotted each of the 38 bursts over time, a pattern began to emerge: One or two bursts would occur over four days, followed by a 12-day period without any bursts, after which the pattern would repeat. This 16-day cycle occurred again and again over the 500 days that they observed the source.
A Big Unknown
Exactly what phenomenon is behind this new extragalactic rhythm is a big unknown, although the team explores some ideas in their new paper.
One possibility is that the periodic bursts may be coming from a single compact object, such as a neutron star, that is both spinning and wobbling—an astrophysical phenomenon known as precession. Assuming that the radio waves are emanating from a fixed location on the object, if the object is spinning along an axis and that axis is only pointed toward the direction of Earth every four out of 16 days, then we would observe the radio waves as periodic bursts.
Another possibility involves a binary system, such as a neutron star orbiting another neutron star or black hole. If the first neutron star emits radio waves, and is on an eccentric orbit that briefly brings it close to the second object, the tides between the two objects could be strong enough to cause the first neutron star to deform and burst briefly before it swings away. This pattern would repeat when the neutron star swings back along its orbit.
Cloud Emitting Stars?
The researchers considered a third scenario, involving a radio-emitting source that circles a central star. If the star emits a wind, or cloud of gas, then every time the source passes through the cloud, the gas from the cloud could periodically magnify the source’s radio emissions.
“Maybe the source is always giving off these bursts, but we only see them when it’s going through these clouds, because the clouds act as a lens,” Masui says.
Mystery Known as Magnetars?
Perhaps the most exciting possibility is the idea that this new FRB, and even those that are not periodic or even repeating, may originate from magnetars—a type of neutron star that is thought to have an extremely powerful magnetic field. The particulars of magnetars are still a bit of a mystery, but astronomers have observed that they do occasionally release massive amounts of radiation across the electromagnetic spectrum, including energy in the radio band.
“People have been working on how to make these magnetars emit fast radio bursts, and this periodicity we’ve observed has since been worked into these models to figure out how this all fits together,” Masui says.
Very recently, the same group made a new observation that supports the idea that magnetars may in fact be a viable source for fast radio bursts. In late April, CHIME picked up a signal that looked like a fast radio burst, coming from a flaring magnetar, some 30,000 light years from Earth. If the signal is confirmed, this would be the first FRB detected within our own galaxy, as well as the most compelling evidence of magnetars as a source of these mysterious cosmic sparks.
Source: Amiri, M., Andersen, B., Bandura, K. et al. Periodic activity from a fast radio burst source. Nature 582, 351–355 (2020). doi.org/10.1038/s41586-020-2398-2
The Daily Galaxy, Max Goldberg, via Massachusetts Institute of Technology
Image credit: neutron star, Shutterstock
Health authority warns of possible COVID-19 exposure at Vancouver bar and nightclub – Yahoo News Canada
Vancouver Coastal Health is asking anyone who visited the bar and nightclub areas of the Hotel Belmont in downtown Vancouver on June 27 and 29 to monitor themselves for symptoms of COVID-19.
Someone who tested positive for coronavirus was in those parts of the hotel on those days, the health authority said in a statement Monday.
There is no risk to anyone who visited the hotel outside those dates, the statement added.
Jasmine Mooney, director of marketing and partner at Hotel Belmont, said protocols are being followed.
“We are working diligently alongside, and following all recommendations from Vancouver Coastal Health, Work Safe BC and The Provincial Health Officer,” she said.
People who may have been exposed are being told to monitor themselves for 14 days and continue their daily activities.
If they develop symptoms of COVID-19, Vancouver Costal Health is asking that they get tested and immediately self-isolate.
Symptoms of COVID-19 may include fatigue, loss of appetite, fever, cough, sore throat, fatigue, runny nose, sore throat loss of smell or diarrhea.
The virus is spread by respiratory droplets when an infected person coughs or sneezes.
It can also spread when a healthy person touches an object or surface with the virus on it and then touches their mouth, nose or eyes before washing their hands.
COVID-19: Vancouver bar patrons may have been exposed to virus – Cape Breton Post
Vancouver Coastal Health is alerting bar patrons who were at Vancouver’s Hotel Belmont a week ago that they may have been exposed to the novel coronavirus.
The VCH says individuals who tested positive for COVID-19 attended the hotel’s bar and nightclub on both June 27 and 29.
Bar-goers who patronized the Hotel Belmont, located at the corner of Nelson and Granville streets, on either of those nights are advised to monitor themselves for 14 days.
“As long as they remain healthy and do not develop symptoms, there is no need to self-isolate and they should continue with their usual daily activities. If you have no symptoms, testing is not recommended because it is not accurate or useful,” the VCH said in a statement.
“If you develop any of these symptoms of COVID-19, please seek COVID-19 testing and immediately self-isolate. Please call ahead and wear a mask when seeking testing.”
The VCH said there is no known risk to anyone who attended the Hotel Belmont outside these two dates.
Copyright Postmedia Network Inc., 2020
Italy's melting glaciers face new threat: Pink ice – Deutsche Welle
Glacier scientists are investigating the appearance of pink ice at Italy’s Presena Glacier, an Alpine region known for skiing and outdoor sports. Research suggests the algae could contribute to increased glacial melt.
Striking photos and videos have been making the rounds on social media in recent days, with people marveling over the appearance of pink ice in the Italian Alps.
The colored ice — known as “watermelon snow” — has been spotted at the Presena Glacier, a popular winter sports area in Italy’s northern Trentino region, which is already feeling the effects of climate change. The area has seen at least 15% of its glaciers retreat since the beginning of the century, and researchers are now looking into whether the proliferation of this natural phenomenon, caused by algae, could speed up the melting process even further.
- Even if we act swiftly to curb carbon emissions in the coming decades, more than a third of the world’s remaining glaciers are expected to disappear by the end of the century
- Glaciers in the European Alps have shrunk by about half since 1900, according to the European Environment Agency. Climate scientists have warned the Alps could be ice free by 2100 if nothing is done to curb CO2 emissions
- Algal bloom — more commonly associated with the world’s oceans — also darkens the surface of glaciers, increasing the amount of sun they absorb and, therefore, how quickly they melt
- The algae found in Italy, likely Chlamydomonas nivalis, are quite common in the Alps and snowy regions around the world, according to Biagio Di Mauro of Italy’s National Research Council
Algae: Bad news for glacial melt
Algae found in the Alps remain dormant during the winter, and only begin to spread on the ice in the spring and summer months when conditions are ideal: increased light and nutrients, plenty of meltwater and a temperature slightly above freezing.
It turns shades of pink and red when exposed to sunlight, which causes it to produce a naturally protective red carotene layer to shield it from harmful ultraviolet radiation.
Di Mauro says the ice, darkened by the algae, absorbs the sun’s rays and melts faster, eating away at the glacier
Chlamydomonas nivalis, which exhibits its red coloring in the closeup, uses pollutants carried in snow as food
But it doesn’t just give snow the look of strawberry gelato. Algal bloom can also tint ice shades of brown, violet yellow or green, as seen in a recent survey that analyzed the slushy coastal regions of Antarctica where warmer temperatures and the excrement of marine animals and birds cause it to spread.
Initial reports suggested the algae might be Ancylonema nordenskioeldii, a species common on the ice sheet in southwest Greenland. In a paper published earlier this year, Di Mauro wrote about his discovery of the first signs of this algae at the Morteratsch Glacier in Switzerland.
“Warm summers and dry winters create the perfect environment for the algae to grow. So, in the future the presence of algae on snow and ice could be favored by climate change,” Di Mauro told DW, though he said that remained to be proven.
Di Mauro said it was still unclear how the algae had made its way to the Alps from Greenland, or whether it had already spread elsewhere. But, he added, “I would not be surprised to find it on other glaciers in the Alps.”
Algae ‘spectacular,’ but not glaciers’ main threat
No matter the color, the algae don’t help the already endangered glaciers. The bright, white surface of a typical glacier generally has a high albedo, meaning it reflects around 80% of the sun’s radiation back into the atmosphere. But as the algae spread over the surface of the glacier, it darkens the ice and causes it to absorb more solar radiation, heating the glacier and speeding up the melting process.
This isn’t a new problem for glaciers, though. Matthias Huss, a glaciology professor at ETH Zurich, told DW in an email that organic material, dust and combustion residue — soot and ash — can accumulate on glaciers over time and “significantly” reduce their ability to reflect the sun’s rays.
Huss doesn’t think the pink algae will affect “glacier retreat significantly.” He said that while the pink algae are “very spectacular,” they only last for a relatively short time and aren’t very widespread in the Alps. He believes it’s possible that algae may contribute to a slight additional reduction in ice volume by the end of the century, but said more research was necessary.
Some ski resorts have begun covering their slopes with insulating tarps in the summer, preserving up to 70% of the snow
The main cause of glacial melt, however, continues to be climate change. In a 2019 study published by the European Geosciences Union (EGU), Huss said that if nothing is done to curb global CO2 emissions “the Alps will be mostly ice free by 2100, with only isolated ice patches remaining at high elevation, representing 5% or less of the present-day ice volume.”
The study, co-authored by Huss, Harry Zekollari of the Delft University of Technology and Daniel Farinotti of ETH Zurich, used computer models to examine ice flow and melt processes. It showed that glaciers in the Alps were already on track to lose about 50% of their total volume by mid-century, no matter what happens with emissions. Algae growth did not factor into their projections.
‘Alps are Europe’s water tower’
Ice fields are an integral part of the Alpine ecosystem and economy, as they attract tourists and “act as natural fresh water reservoirs” for agriculture and hydroelectricity, said the EGU study.
“The Alps are Europe’s water tower,” said Huss. “If the glaciers begin to provide less water during the summer, this could become problematic in periods of drought.” However, he said, given that the glaciers aren’t expected to disappear completely before the end of the century, in the worst-case scenario they will likely provide enough water for decades to come.
According to Zekollari, it might be possible to save “approximately one-third of the present-day [glacial] volume by the end of the century,” if the world follows CO2 curbs on par with the 2015 Paris climate agreement.
But he said the signs weren’t very positive at the moment, with the US abandoning the Paris accord and the EU still stuck in discussions of how it will reach its “ambitious goals.”
“It is clear that our actions today and decisions we make in the near future will have a large effect on the evolution of glaciers in the second part of the 21st century,” said Zekollari.
Toronto's real estate market is rebounding fast as pandemic restrictions lift – blogTO
Deutsche Bank fined $150M US for failing to monitor Jeffrey Epstein transactions – CBC.ca
Health authority warns of possible COVID-19 exposure at Vancouver bar and nightclub – Yahoo News Canada
Silver investment demand jumped 12% in 2019 – report – MINING.com
Iran anticipates renewed protests amid social media shutdown
Richmond BBQ spot speaks out about coronavirus rumours Vancouver Is Awesome
- Sports11 hours ago
Blue Jays’ 60-game schedule for the abbreviated 2020 MLB regular season – Bluebird Banter
- News20 hours ago
This couple can't be together in Canada because of COVID-19, so they're moving to Serbia – CTV News
- Sports21 hours ago
Trump demands Bubba Wallace apology, alleges noose incident was 'a hoax' – CBC.ca
- Tech17 hours ago
Video game giant Ubisoft shakes up executive ranks as it deals with harassment claims – CBC.ca
- Politics21 hours ago
Coun. Lorelei Nicoll announces end to 12-year municipal politics career in Halifax – Globalnews.ca
- Sports22 hours ago
Multiple Jays players left behind in Florida after another COVID-19 positive – Toronto Sun
- Tech21 hours ago
29 workers test positive for COVID-19 at Ontario mushroom farm – CP24 Toronto's Breaking News
- Politics9 hours ago
Why Guyana’s political stalemate matters – The Washington Post