Update Saturday, Nov. 25 - Dec. 1, 2017
Stellar encore: Dying star keeps coming back big time
This illustration made available by the
European Southern Observatory in 2014 shows dust surrounding a supernova
explosion. On Wednesday, Nov. 8, 2017, astronomers reported that a star
500 million light-years away exploded in 1954 and apparently again in
2014. The research confounds scientists who thought they knew how dying
stars ticked. (M. Kornmesser/ESO via AP)
Fla. (AP) - Death definitely becomes this
reported Wednesday on a massive, distant star that exploded in 2014 -
and also, apparently back in 1954. This is one supernova that refuses to
bite the cosmic dust, confounding scientists who thought they knew how
dying stars ticked.
star is 500 million lightyears away - one lightyear is equal to 5.9
trillion miles (9.5 trillion kilometers) - in the direction of the Big
Bear constellation. It was discovered in 2014 and, at the time,
resembled your basic supernova that was getting fainter.
But a few months
later, astronomers at the California-based Las Cumbres Observatory saw
it getting brighter. They’ve seen it grow faint, then bright, then faint
again five times. They’ve even found past evidence of an explosion 60
years earlier at the same spot.
typically fade over 100 days. This one is still going strong after 1,000
days, although it’s gradually fading.
surprising and very exciting,” said astrophysicist Iair Arcavi of the
University of California, Santa Barbara who led the study. “We thought
we’ve seen everything there is to see in supernovae after seeing so many
of them, but you always get surprised by the universe. This one just
really blew away everything we thought we understood about them.”
The supernova -
officially known as iPTF14hls - is believed to have once been a star up
to 100 times more massive than our sun. It could well be the biggest
stellar explosion ever observed, which might explain its death-defying
It could be
multiple explosions occurring so frequently that they run into one
another or perhaps a single explosion that repeatedly gets brighter and
fainter, though scientists don’t know exactly how this happens.
One possibility is
that this star was so massive, and its core so hot, that an explosion
blew away the outer layers and left the center intact enough to repeat
the entire process. But this pulsating star theory still doesn’t explain
everything about this supernova, Arcavi said.
University’s astronomy chairman, Avi Loeb, who was not involved in the
study, speculates a black hole or magnetar - a neutron star with a
strong magnetic field - might be at the center of this never-before-seen
behavior. Further monitoring may better explain what’s going on, he
Las Cumbres, a
global network of robotic telescopes, continues to keep watch.
Scientists do not
know whether this particular supernova is unique; it appears rare since
no others have been detected.
“We could actually
have missed plenty of them because it kind of masquerades as a normal
supernova if you only look at it once,” Arcavi said.
forever - not even this super supernova.
star will go out at some point,” Arcavi said. “I mean, energy has to run
Study: Great white sharks are swimming farther and deeper
In this Sept. 13, 2012 file photo, Captain
Brett McBride places his hand on the snout of the crew’s first specimen
while scientists collect blood, tissue samples and attach tracking
devices on the research vessel Ocearch off the coast of Chatham, Mass.
Before release, the nearly 15-foot, 2,292-pound great white shark was
named Genie for famed shark researcher Eugenie Clark. (AP Photo/Stephan
Boston (AP) - The movements
of great white sharks in the Pacific and Indian oceans have long been
the subject of academic study, but new research is just starting to shed
light on the behavior of their Atlantic Ocean counterparts.
Researchers in Massachusetts say
white sharks appear to venture offshore farther, with more frequency and
at greater depths than previously known in the Atlantic.
Some of the 32 sharks tracked
between 2009 and 2014 ended up as far east as the Azores, the Portuguese
island chain located more than 2,300 miles (3,701 kilometers) from Cape
Cod, where most of the animals were initially outfitted with satellite
They also were found to make
frequent deep dives - as far down as 3,700 feet (1,127 meters) - and
spend more time at those dark depths than previous studies in the
The team, which included scientists
from the state Division of Marine Fisheries, the Massachusetts Institute
of Technology and the Woods Hole Oceanographic Institution, had its
findings published last week in Marine Ecology Progress Series,
a prominent scientific journal.
“Everything we knew previously
indicated that the white shark in the Atlantic is more
coastally-oriented, moving north-to-south and remaining on the
continental shelf,” explained Gregory Skomal, the study’s lead author.
“So what we’re now describing is this other component, this offshore
movement into open ocean.”
Skomal says the work has
implications for shark conservation efforts since it extends the known
habitat for these ancient predators. White sharks are not considered
endangered or threatened, but it’s illegal to hunt them in U.S. waters.
“You’ve got U.S. protection within
200 miles of shore, but you have sharks clearly leaving that protection
that are vulnerable to harvest,” Skomal said. “We need to engage other
countries fishing in these waters to talk about putting similar
protections in place.”
The research is exciting because it
represents the “first real insights into the movement patterns of white
sharks” in the northern part of the Atlantic, says Tobey Curtis, a
Massachusetts-based shark researcher for the National Marine Fisheries
Service who was not involved with the study.
“Prior to this, we were only able
to piece together information about their distribution from widely
scattered reports from fishermen, scientists and the public,” he said.
“Having tracks of individual sharks really helps fill in the gaps, and
provides a more complete picture of white shark movements and
The study seems to hew closely to
what’s been observed of white sharks in other oceans - that juveniles
tend to stay in the relatively shallower waters of the continental shelf
where food sources abound, while adults are more apt to venture into
open ocean, observes Christopher Lowe, a shark researcher at California
State University in Long Beach also not involved with the research.
Indeed, most of the tagged sharks
in the Atlantic study generally followed a north-south migration along
the Eastern Seaboard.
They headed to Newfoundland and New
England waters in the summer, then down south to the Carolinas and even
the Bahamas for the winter.
Lowe says it remains to be seen
what impact continued growth of white shark populations in the Atlantic
has on these habits, or whether climate change is playing a role.
Another key question is finding out
what these sharks are actually doing so far offshore.
Researchers in northern California
suggest offshore movements are for mating, a ritual that has never been
observed among white sharks. But Skomal and his team believe the animals
are more likely foraging - it’s just not immediately obvious what
they’re feeding on.
“That’s the great mystery right
now,” he said.
Update Saturday, Nov. 18 - Nov. 24, 2017
Pence pledges that US will
go to the moon, Mars and beyond
Vice President Mike Pence speaks in front of
NASA’s Space Shuttle Discovery at the National Space Council first
meeting at the Steven F. Udvar-Hazy Center, Thursday, Oct. 5, 2017 in
Chantilly, Va. (AP Photo/Andrew Harnik)
- Seated before the grounded space shuttle
Discovery, a constellation of Trump administration officials used
soaring rhetoric to vow to send Americans back to the moon and then on
celestial aspirations, top officials moved to what National Intelligence
Director Dan Coats called “a dark side” to space policy. Coats, Vice
President Mike Pence, other top officials and outside space experts said
the United States has to counter and perhaps match potential enemies’
ability to target U.S. satellites.
cabinet secretaries and White House advisers gathered in the shadow of
the shuttle at the Smithsonian Institution’s Steven F. Udvar-Hazy Center
to chart a new path in space - government, commercial and military - for
the country. It was the first meeting of the National Space Council,
revived after it was disbanded in 1993.
But details, such
as how much the new ideas will cost, were scant and outside experts said
they’ve heard grandiose plans before only to see them fizzle instead of
“We will return
American astronauts to the moon, not only to leave behind footprints and
flags, but to build the foundation we need to send Americans to Mars and
beyond,” Pence said.
leaders say they and NASA are building the spaceships to get there. And
they’re promising that in five years, astronauts could be working around
president of the space company Orbital ATK, said NASA’s Orion capsule
and super-sized Space Launch System rocket should be ready in a couple
years, so flying around the moon and even making a lunar orbiting
outpost is within reach. But he said a lunar landing would take longer.
Blue Origin rocket company chief executive officer Bob Smith said his
firm could have a lunar lander program ready within five years.
No humans have been
on the moon since Apollo 17 in December 1972. Only 12 men have set foot
on the moon, all have been Americans.
George H.W. Bush and George W. Bush proposed returns to the moon and
then going on to Mars. Barack Obama rerouted the moon plan to an
asteroid as a first-stop with Mars as the goal. All plans had lack of
money keep them from coming true, said space expert Brian Weeden of the
Secure World Foundation. He wasn’t part of the council meeting.
“Is it going to
happen? Who knows? I feel like I’ve been disappointed so many times I
refuse to get excited,” said Roger Launius, a longtime space historian.
And Gwynn Shotwell,
president of SpaceX, said her company next year will launch astronauts
to the International Space Station, the first American launch of people
since 2011. After the 2003 space shuttle Columbia broke apart on
descent, then-president George W. Bush announced the phasing out of the
space shuttle program. Eventually, NASA started building new
multibillion dollar ships, the Orion capsule and the SLS mega-rocket.
Pence several times
bemoaned a U.S. space program that had fallen behind, asking space
executives what they thought.
out-innovating the world in space launch,” Shotwell said, noting that
her company had launched 13 rockets this year, more than any other
After talking about
how “we will blaze new trails into that great frontier” Pence turned the
discussion to the dangers of space and how much of the U.S. intelligence
system and day-to-day life are dependent on commercial satellites
operating safely. And he and others outlined threats to those satellites
from potential enemies that could cripple American security and daily
that satellites could be destroyed and debris in orbit could ruin
Pence asked if the
U.S. should “weaponize” space.
“The choice whether
or not to weaponize space is not one that we can make. We can only
decide to match and raise our adversaries who are already weaponizing
space,” former NASA chief Michael Griffin said. “That horse is already
out of the barn.”
National Security Adviser H.R. McMaster said the country needs to “deter
and when necessary defeat adversaries’ counter-space efforts... We may
not start it but we will finish it.”
Update Saturday, Nov. 11 - Nov. 17, 2017
What cosmic crash confirmed:
Einstein was as good as gold
Julie McEnery, an astrophysicist at NASA’s
Goddard Space Flight Center in Greenbelt, Md., speaks at the National
Press Club in Washington, Monday, Oct. 16, 2017, during an announcement
about one of the most violent events in the cosmos that was witnessed
completely for the first time in August and tells scientists where gold
and other heavy elements come from. (AP Photo/Susan Walsh)
- When two extremely dense neutron stars
crashed together in a distant galaxy, astronomers struck scientific
gold, confirming previously unproven theories, including some from
announced that after picking up two faint signals in mid-August, they
were able to find the location of the long-ago crash and see the end of
it play out. Measurements of the light and other energy that the crash
produced helped them answer some cosmic questions.
starting with Einstein, figured that when two neutron stars collide they
would produce a gravitational wave, a ripple in the universe-wide fabric
of space-time. Four other times that these waves were detected they were
the result of merging black holes. This is the first time scientists
observed one caused by a neutron star crash.
Where gold comes from
The Big Bang
created light elements like hydrogen and helium. Supernovas created
medium elements, up to iron. But what about the heavier ones like gold,
platinum and uranium? Astronomers thought they came from two neutron
stars colliding, and when they saw this crash they confirmed it. One
astronomer described as a “giant train wreck that creates gold.” They
estimate that this one event generated an amount of gold and platinum
that outweighs the entire Earth by a factor of 10.
Gamma ray bursts
are some of the most energetic and deadly pulses of radiation in the
universe. Astronomers weren’t quite sure where short gamma ray bursts
came from, but figured that a crash of neutron stars was a good bet.
Watching this event confirmed the theory.
the universe is expanding, and they use a figure called the Hubble
Constant to describe how fast. Two different ways scientists have of
measuring this speed of expansion yields two numbers that are somewhat
close to each other, but not quite the same. By measuring how far the
gravitational wave had to travel, astronomers came up with another
estimate that was between the earlier two, but it also comes with a
large margin of error.
How fast do rays and waves go?
The crash showed
that gravitational waves and gamma rays travel at nearly the speed of
light - which is what Einstein’s General Relativity theory says. NASA
astrophysicist Julie McEnery said: “Yet again, Einstein passes another
Update Saturday, Nov. 4 - Nov. 10, 2017
Scientists witness huge cosmic crash, find origins of gold
This illustration provided by the Carnegie
Institution for Science depicts the collision of two neutron stars detected
on Aug. 17, 2017. The explosion threw matter, light, radiation and
gravitational waves into space. The discovery was reported on Monday, Oct.
16, 2017. (Robin Dienel/Carnegie Institution for Science via AP)
Washington (AP) -
It was a faint signal, but it told of one of the most violent acts in the
universe, and it would soon reveal secrets of the cosmos, including how gold
Astronomers around the
world reacted to the signal quickly, focusing telescopes located on every
continent and even in orbit to a distant spot in the sky.
What they witnessed in
mid-August and revealed Monday, Oct. 16, was the long-ago collision of two
neutron stars - a phenomenon California Institute of Technology’s David H.
Reitze called “the most spectacular fireworks in the universe.”
“When these things
collide, all hell breaks loose,” he said.
Measurements of the
light and other energy emanating from the crash have helped scientists
explain how planet-killing gamma ray bursts are born, how fast the universe
is expanding, and where heavy elements like platinum and gold come from.
“This is getting
everything you wish for,” said Syracuse University physics professor Duncan
Brown, one of more than 4,000 scientists involved in the blitz of science
that the crash kicked off. “This is our fantasy observation.”
It started in a galaxy
called NGC 4993, seen from Earth in the Hydra constellation. Two neutron
stars, collapsed cores of stars so dense that a teaspoon of their matter
would weigh 1 billion tons, danced ever faster and closer together until
they collided, said Carnegie Institution astronomer Maria Drout.
The crash, called a
kilonova, generated a fierce burst of gamma rays and a gravitational wave, a
faint ripple in the fabric of space and time, first theorized by Albert
“This is like a cosmic
atom smasher at a scale far beyond humans would be capable of building,”
said Andy Howell, a staff scientist at the Las Cumbres Observatory. “We
finally now know what happens when an unstoppable force meets an immovable
object and it’s a kilonova.”
The crash happened 130
million years ago, while dinosaurs still roamed on Earth, but the signal
didn’t arrive on Earth until Aug. 17 after traveling 130 million
light-years. A light-year is 5.88 trillion miles.
Signals were picked up
within 1.7 seconds of each other, by NASA’s Fermi telescope, which detects
gamma rays, and gravity wave detectors in Louisiana and Washington State
that are a part of the LIGO Laboratory, whose founders won a Nobel Prize
earlier this month. A worldwide alert went out to focus telescopes on what
became the most well-observed astronomical event in history.
Before August, the only
other gravity waves detected by LIGO were generated by colliding black
holes. But black holes let no light escape, so astronomers could see
This time there was
plenty to see, measure and analyze: matter, light, and other radiation. The
Hubble Space Telescope even got a snapshot of the afterglow.
Finding where the crash
happened wasn’t easy. Eventually scientists narrowed the location down to
100 galaxies, began a closer search of those, and found it in the ninth
galaxy they looked at.
It is like “the classic
challenge of finding a needle in the haystack with the added challenge that
the needle is fading away and the haystack is moving,” said Marcelle
Soares-Santos, an astrophysicist at Brandeis University.
“The completeness of
this picture from the beginning to the end is unprecedented,” said Columbia
University physics professor Szabolcs Marka. “There are many, many
extraordinary discoveries within the discovery.”
The colliding stars
spewed bright blue, super-hot debris that was dense and unstable. Some of it
coalesced into heavy elements, like gold, platinum and uranium. Scientists
had suspected neutron star collisions had enough power to create heavier
elements, but weren’t certain until they witnessed it.
“We see the gold being
formed,” said Syracuse’s Brown.
Calculations from a
telescope measuring ultraviolet light showed that the combined mass of the
heavy elements from this explosion is 1,300 times the mass of Earth. And all
that stuff - including lighter elements - was thrown out in all different
directions and is now speeding across the universe.
Perhaps one day the
material will clump together into planets the way ours was formed, Reitze
said - maybe ones with rich veins of precious metals.
“We already knew that
iron came from a stellar explosion, the calcium in your bones came from
stars and now we know the gold in your wedding ring came from merging
neutron stars,” said University of California Santa Cruz’s Ryan Foley.
The crash also helped
explain the origins of one of the most dangerous forces of the cosmos -
short gamma ray bursts, focused beams of radiation that could erase life on
any planet that happened to get in the way. These bursts shoot out in two
different directions perpendicular to where the two neutron stars first
crash, Reitze said.
Luckily for us, the
beams of gamma rays were not focused on Earth and were generated too far
away to be a threat, he said.
Scientists knew that
the universe has been expanding since the Big Bang. By using LIGO to measure
gravitational waves while watching this event unfold, researchers came up
with a new estimate for how fast that is happening, the so-called Hubble
Constant. Before this, scientists came up with two slightly different
answers using different techniques. The rough figure that came out of this
event is between the original two, Reitze said.
The first optical
images showed a bright blue dot that was very hot, which was likely the
start of the heavy element creation process amid the neutron star debris,
Drout said. After a day or two that blue faded, becoming much fainter and
redder. And after three weeks it was completely gone, she said.
This almost didn’t
happen. Eight days after the signal came through, the LIGO gravitational
waves were shut down for a year’s worth of planned upgrades. A month later
the whole area where the crash happened would have been blocked from
astronomers’ prying eyes by the sun.
with the search for gravitational waves said this was the event they had
prepared for over more than 20 years.
The findings are “of
spectacular importance,” said Penn State physicist Abhay Ashtekar, who
wasn’t part of the research. “This is really brand new.”
Almost all of the
discoveries confirmed existing theories, but had not been proven - an
encouraging result for theorists who have been trying to explain what is
happening in the cosmos, said France Cordova, an astrophysicist who directs
the National Science Foundation.
“We so far have been
unable to prove Einstein wrong,” said Georgia Tech physics professor Laura
Cadonati. “But we’re going to keep trying.”