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A12 science
Friday 6 November 2020
Flash of luck: Astronomers find cosmic radio burst source

about $15,000. Each is "the
size of a large bucket. It's a
piece of 6-inch metal pipe
with two literal cake pans
around it," the doctoral stu-
dent said. They are crude
instruments designed to
look at a giant chunk of the
sky — about a quarter of it
— and see only the bright-
est of radio flashes.
Bochenek figured he had
maybe a 1-in-10 chance of
spotting a fast radio burst in
a few years. But after one
year, he hit pay dirt.
The Canadian observatory
in British Columbia is more
focused and refined but is
aimed at a much smaller
chunk of the sky, and it was
able to pinpoint the source
to the magnetar in the con-
stellation Vulpecula.
Because the bursts are af-
fected by all the material
they pass through in space,
astronomers might be able
to use them to better un-
derstand and map the
invisible-to-us material be-
tween galaxies and "weigh"
the universe, said Jason
This image from video animation provided by NASA in November 2020 depicts a powerful X-ray burst erupting from a magnetar – a Hessels, chief astronomer
supermagnetized version of a stellar remnant known as a neutron star. for the Netherlands Institute
Associated Press
for Radio Astronomy, who
wasn't part of the research.
Astronomers have had as
By SETH BORENSTEIN of star called a magne- astronomer Casey Law of travel millions or billions of many 50 different theo-
AP Science Writer tar that's 32,000 light-years the California Institute of light-years are "tens of thou- ries for what causes these
A flash of luck helped as- from Earth, according to Technology, who wasn't sands to millions of times fast radio bursts, including
tronomers solve a cos- four studies in Wednesday's part of the research. more powerful than any- aliens, and they emphasize
mic mystery: What causes journal Nature. There are maybe a dozen thing we have detected in that magnetars may not be
powerful but fleeting radio It was not only the first fast or so of these magnetars our galaxy," said co-author the only answer, especially
bursts that zip and zigzag radio burst traced to a in our galaxy, apparently Daniele Michilli, an astro- since there seem to be two
through the universe? source, but the first ema- because they are so young physicist at McGill and part types of fast radio bursts.
Scientists have known nating from our galaxy. As- and part of the star birth of the Canadian team. Some, like the one spotted
about these energetic tronomers say there could process, and the Milky Way Scientists think these are in April, happen only once,
pulses — called fast radio be other sources for these is not as flush with star births so frequent that they may while others repeat them-
bursts — for about 13 years bursts, but they are now as other galaxies, said Cor- happen more than 1,000 selves often.
and have seen them com- sure about one guilty party: nell University Shami Chat- times a day outside our Michilli said his team has
ing from outside our galaxy, magnetars. terjee, who wasn't part of galaxy. But finding them traced one outburst that
which makes it harder to Magnetars are incredibly either discovery team. isn't easy. happens every 16 days to
trace them back to what's dense neutron stars, with This burst in less than a sec- "You had to be looking at a nearby galaxy and is get-
causing them. Making it 1.5 times the mass of our ond contained about the the right place at the right ting close to pinpointing
even harder is that they sun squeezed into a space same amount of energy millisecond," Cornell's Chat- the source.
happen so fast, in a couple the size of Manhattan. that our sun produces in terjee said. "Unless you were Some of these young mag-
of milliseconds. They have enormous mag- a month, and still that's very, very lucky, you're not netars are only a few de-
Then this April, a rare but netic fields that buzz and far weaker than the radio going to see one of these." cades old, "and that's what
considerably weaker burst crackle with energy, and bursts detected coming Even though this is a fre- gives them enough ener-
coming from inside our sometimes flares of X-rays from outside our galaxy, quent occurrence outside gy to produce repeating
own Milky Way galaxy was and radio waves burst from said Caltech radio astrono- the Milky Way, astronomers fast radio bursts," Cornell's
spotted by two dissimilar them, according to McGill mer Christopher Bochenek. have no idea how often Chatterjee said.
telescopes: one a Califor- University astrophysicist Zig- He helped spot the burst these bursts happen inside Tracking even one outburst
nia doctoral student's set gy Pleunis, a co-author of with handmade antennas. our galaxy. is a welcome surprise and
of handmade antenna the Canadian study. These radio bursts aren't "We still don't know how an important finding, he
s, which included actual The magnetic field around dangerous to us, not even lucky we got," Bochenek said.
cake pans, the other a $20 these magnetars "is so the more powerful ones said. "This could be a once- "No one really believed that
million Canadian observa- strong any atoms nearby from outside our galaxy, as- in-five-year thing or there we'd get so lucky," Chatter-
tory. are torn apart and bizarre tronomers said. could be a few events to jee said. "To find one in our
They tracked that fast ra- aspects of fundamental The ones that come from happen each year." own galaxy, it just puts the
dio burst to a weird type physics can be seen," said outside our galaxy and Bochenek's antennas cost cherry on top."q