The weird, repeating signals from deep space just tripled - CNET - Canadanewsmedia
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The weird, repeating signals from deep space just tripled – CNET

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We’re picking up more signals from deep space.


Danielle Futselaar

Scientists suddenly have a whole lot more data on one of the strangest and most recent mysteries in the cosmos, so-called fast radio bursts (FRBs). First discovered in 2007, these fleeting blasts of radio waves originate thousands, millions or even billions of light years from Earth. 

FRBs have influenced the design of new radio telescopes like the Canadian Hydrogen Intensity Mapping Experiment (CHIME). And now a team of Canadian and American researchers using CHIME has reported a major new set of FRB detections that could fine-tune our understanding of where these enigmatic signals come from and what produces them. 

The group says it’s discovered eight new FRBs that repeat.


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“Repeating FRBs are highly valuable from an observational perspective since their repeating nature make them better candidates for localizing their host galaxies and multi-wavelength follow-up observations that can help determine if FRBs emit at wavelengths other than radio,” said Ryan McKinven, one of the researchers who is based at the University of Toronto and co-author of a paper about the FRBs.

Those follow-up observations could provide details about the origins of the strange bursts, he added. A larger sample size of repeating FRBs to study could also help scientists answer one of the obvious questions about non-repeating FRBs: Could they actually be repeating FRBs that just haven’t been recorded as repeating yet?

While dozens of FRBs have been detected and cataloged over the past 12 years, few of those deep space signals had been known to repeat themselves. Two have been documented so far in published, peer-reviewed journals. Two others — one via a Russian radio telescope, the other via Australia — have been reported but not yet reviewed. 

So with this batch of bursts, the number of reported repeaters has tripled — from four to 12. 

The team laid out its findings in a draft paper that’s been submitted to the Astrophysical Journal and was posted this month on the Arxiv pre-print site

Discovering different types of FRBs at an unexpected rate, we will soon open new windows into understanding the cosmological origin of these high-energy astrophysical phenomena,” said co-author Masoud Rafiei-Ravandi of the Perimeter Institute for Theoretical Physics. 

In addition to the sheer number of repeating FRBs discovered in one haul, one of the newfound repeaters appears to be much closer to Earth than the handful of fast radio bursts that have been traced back to a source galaxy. So far, traceable FRBs seem to come from sources on the other side of the universe — we’re talking billions of light years away.

However, in the new paper, the authors suggest that one of the repeating FRBs could actually originate near the edge of our own Milky Way galaxy but caution that more study is needed to better localize the signal. 

“Knowing that we are observing every patch of sky visible to CHIME once every day, it was only a matter of time before we detected a very nearby source,” co-author Pragya Chawla of McGill University said.

Studying relatively nearby FRBs will hopefully allow scientists to get a better idea of just what the heck is throwing off these signals, which could be anything from far-fetched notions like alien starships to the less fantastic but literally more powerful sources, like neutron stars.

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Oxygen on Mars Is Behaving in a Way Scientists Can't Explain – ScienceAlert

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Atmospheric gases on Mars sure provide us with plenty of mystery. First, there was that business with the disappearing, reappearing methane. Now, oxygen levels have been observed rising and falling over the Gale Crater, by amounts that just don’t fit any known chemical processes.

The data comes from Curiosity, the Mars rover that’s been making its slow and methodical trek across the crater floor and up the foot of Mount Sharp in the centre of it.

The robot isn’t just looking down at the rocks beneath its treads; Curiosity also takes readings of the Martian atmosphere to measure the seasonal atmospheric changes. It’s been up there for three Mars years now (that’s six Earth years), and scientists poring over the measurements have noticed that oxygen in the planet’s atmosphere isn’t behaving entirely as expected.

There actually isn’t all that much oxygen on Mars. Most of its thin atmosphere (95 percent by volume) is carbon dioxide, or CO2. The rest is made up of 2.6 percent molecular nitrogen (N2), 1.9 percent argon (Ar), 0.16 percent molecular oxygen (O2), and 0.06 percent carbon monoxide (CO).

(Earth’s atmosphere, by contrast, is mostly nitrogen, at 78.09 percent by volume, and 20.95 percent oxygen.)

On Mars, atmospheric pressure changes over the course of the year. On the winter hemisphere, CO2 freezes over the pole, which causes the pressure to drop across the hemisphere. This results in a hemisphere-to-hemisphere redistribution of gases to equalise atmospheric pressure planet-wide.

In spring, when the polar caps melt and release the CO2, the opposite effect occurs: pressure initially rises in that hemisphere, then evens out as gases are redistributed towards the winter hemisphere.

So, the fluctuations of the other gases are predictable in proportion to the CO2 levels. Or at least, they should be. In the case of nitrogen and argon, it is – these gases have been behaving more or less exactly as expected. But oxygen? Nope.

During spring and summer, oxygen rose by around 30 percent, dropping back to normal levels in autumn. This happened every year, but since the amount by which the oxygen rises varies from year to year, it seems like something is adding the oxygen, and then taking it away again.

There is no known process that can produce this result.

The obvious question for such an odd measurement was whether there could be something wrong with the Quadrupole Mass Spectrometer instrument or software. Several checks saw that it was all working fine.

Another possibility was whether the oxygen could be produced by water or carbon dioxide somehow breaking apart in the atmosphere. This was quickly ruled out too – there’s not nearly enough water in the Martian atmosphere, and CO2 breaks down too slowly to fit the observed fluctuations.

Now, Martian soil does contain a lot of oxygen. But the conditions required to release it have not been observed – and that wouldn’t explain where it disappears to each year. The process whereby solar radiation breaks apart oxygen and it dissipates into space is likewise too slow.

“We’re struggling to explain this,” said planetary scientist Melissa Trainer of NASA’s Goddard Space Flight Center.

“The fact that the oxygen behaviour isn’t perfectly repeatable every season makes us think that it’s not an issue that has to do with atmospheric dynamics. It has to be some chemical source and sink that we can’t yet account for.”

But there is one clue. The methane. It, too, rises dramatically over Mars’ summer months, increasing by up to 60 percent. Sometimes the methane and oxygen levels even seem to rise in tandem. It’s possible that whatever it is that causes the methane fluctuations is also causing the oxygen fluctuations.

What that could be is still a huge question. Both gases can be produced through organic processes – that is, life – and both can be produced through geological processes.

We don’t, as yet, have any evidence that there is life on Mars, but nor can it be ruled out as a cause. (Mars 2020 is going to look for fossils, so maybe we’ll find out soon.)

However, the team believes it is much more likely to be geological.

“We have not been able to come up with one process yet that produces the amount of oxygen we need,” said astronomer Tim McConnochie of the University of Maryland.

“But we think it has to be something in the surface soil that changes seasonally because there aren’t enough available oxygen atoms in the atmosphere to create the behaviour we see.” 

So… any ideas?

The research has been published in the Journal of Geophysical Research: Planets.

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Mini Mercury skips across sun’s vast glare in rare transit – Fernie Free Press

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Mini Mercury skipped across the vast, glaring face of the sun Monday in a rare celestial transit.

Stargazers used solar-filtered binoculars and telescopes to spot Mercury — a tiny black dot — as it passed directly between Earth and the sun on Monday.

The eastern U.S. and Canada got the whole 5 1/2-hour show, weather permitting, along with Central and South America. The rest of the world, except for Asia and Australia, got just a sampling.

Mercury is the solar system’s smallest, innermost planet. The next transit isn’t until 2032, and North America won’t get another shot until 2049.

In Maryland, clouds prevented NASA solar astrophysicist Alex Young from getting a clear peek. Live coverage was provided by observatories including NASA’s orbiting Solar Dynamics Observatory.

“It’s a bummer, but the whole event was still great,” Young wrote in an email. “Both getting to see it from space and sharing it with people all over the country and world.”

At Cape Canaveral, space buffs got a two-for-one. As Mercury’s silhouette graced the morning sun, SpaceX launched 60 small satellites for global internet service, part of the company’s growing Starlink constellation in orbit.

ALSO READ: ‘Very surreal’: B.C. students help design space colony in NASA-backed competition

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Marcia Dunn, The Associated Press


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A Star Ejected from the Milky Way's 'Heart of Darkness' Has Reached a Mind-Blowing Speed – Space.com

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As humankind’s ancestors were learning to walk upright, a star was launched out of the supermassive black hole at the center of our galaxy at a staggering 3.7 million mph (6 million km/h). 

Five million years after this dramatic ejection, a group of researchers, led by Sergey Koposov of Carnegie Mellon University’s McWilliams Center for Cosmology, has spotted the star, known as S5-HVS1, in the Crane-shaped constellation Grus. The star was spotted traveling relatively close to Earth (29,000 light-years away) at unprecedented, searing speeds — about 10 times faster than most stars in our galaxy. 

“The velocity of the discovered star is so high that it will inevitably leave the galaxy and never return,” Douglas Boubert, a researcher at the University of Oxford and a co-author on the study, said in a statement

Related: Top 10 Star Mysteries of All Time

An artist’s impression of te star S5-HVS1 being ejected by the Milky Way galaxy’s supermassive black hole, Sagittarius A*.

(Image credit: James Josephides (Swinburne Astronomy Productions))

“This is super exciting, as we have long suspected that black holes can eject stars with very high velocities. However, we never had an unambiguous association of such a fast star with the galactic center,” Koposov said in the statement. 

The star was discovered with observations from the Anglo-Australian Telescope (AAT), a 12.8-foot (3.9-meter) telescope, and the European Space Agency’s Gaia satellite. The discovery was made as part of the Southern Stellar Stream Spectroscopic Survey (S5), a collaboration of astronomers from Chile, the U.S., the U.K. and Australia. 

Now that the star has been spotted, researchers could track the star back to Sagittarius A*, the black hole at the center of the Milky Way. It also serves as an incredible example of the Hills Mechanism, proposed by astronomer Jack Hills 30 years ago, in which stars are ejected from the centers of galaxies at high speeds after an interaction between a binary-star system and the black hole at the center of the galaxy.

The location and direction of the star S5-HVS1 in the night sky. The star is rocketing away from the center of our galaxy.

(Image credit: Sergey Koposov)

“This is the first clear demonstration of the Hills Mechanism in action,” Ting Li, a fellow  at the Carnegie Observatories and Princeton University who led the S5 collaboration, said in the statement. “Seeing this star is really amazing as we know it must have formed in the galactic center, a place very different to our local environment. It is a visitor from a strange land.”

“While the main science goal of S5 is to probe the stellar streams — disrupting dwarf galaxies and globular clusters — we dedicated spare resources of the instrument to searching for interesting targets in the Milky Way, and voila, we found something amazing for ‘free.’ With our future observations, hopefully we will find even more!” Kyler Kuehn, deputy director of technology at the Lowell Observatory who is part of the S5 executive committee, added in the statement.

This discovery was published in a study on Nov. 4 in the journal the Monthly Notices of the Royal Astronomical Society. 

Follow Chelsea Gohd on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

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