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Ultra-High Energy Cosmic Rays Come From Outside The Milky Way

Travelling with a speed of lights, cosmic rays are atomic nuclei. Scientist says that high energy cosmic rays coming from outer space are hitting the earth.

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Cosmic rays
Source: Pixaby

New York, September 24, 2017: Researchers have found that some ultra-high energy cosmic rays that occasionally hit Earth come from a distant source outside the Milky Way.

Cosmic rays are atomic nuclei that travel through space at speeds close to that of light. Low-energy cosmic rays come from the Sun or from our own galaxy, but the origin of the highest-energy particles has been the subject of debate ever since they were first discovered fifty years ago.

Do they come from our Galaxy or from distant extragalactic objects?

The study published in the journal Science demonstrated that those cosmic rays with energies a million times greater than that of the protons accelerated in the Large Hadron Collider – the world’s largest and most powerful particle accelerator – come from much further away than from our own galaxy.

They were detected from 2004 to 2016 at the largest cosmic ray observatory ever built, the Pierre Auger Observatory in Argentina.

“We are now considerably closer to solving the mystery of where and how these extraordinary particles are created — a question of great interest to astrophysicists,” said Karl-Heinz Kampert from University of Wuppertal in Germany.

“Our observation provides compelling evidence that the sites of acceleration are outside the Milky Way,” Kampert who is spokesperson for the Auger Collaboration, which involves more than 400 scientists from 18 countries, said.

Cosmic rays are the nuclei of elements from hydrogen to iron. The highest-energy cosmic rays, those of interest in this study, only strike about once per square kilometre per year — equivalent to hitting the area of a soccer field about once per century.

Such rare particles are detectable because they create showers of secondary particles — including electrons, photons and muons – as they interact with the nuclei in the atmosphere.

These cosmic ray showers spread out, sweeping through the atmosphere at the speed of light in a disc-like structure, like a dinner plate but several kilometres in diameter.

ALSO READ: NASA’s Asteroid-chasing Spacecraft Osiris-Rex Swinging by Earth on Way to Space Rock

At the Auger Observatory, the shower particles are detected through the light they produce in several of 1,600 detectors, spread over 3,000 square kilometres of western Argentina and each containing 12 tons of water.

Tracking these arrivals tells scientists the direction from which the cosmic rays came.

After racking up detections of more than 30,000 cosmic particles, the scientists found one section of the sky was producing significantly more than its share.

The probability of this happening by a random fluctuation is extremely small, the scientists said — a chance of about two in ten million.

“This result unequivocally establishes that ultra-high energy cosmic rays are not just random wanderers of our nearby universe,” Paolo Privitera of University of Chicago who heads the US groups participating in the project, said. (IANS)

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Astronomers Discover New ‘Mid-size’ Black Hole 100,000 Times More Massive than the Sun

Scientists predict that nearly 100 million of these small black holes should exist in the Milky Way, however only about 60 have been found till now

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Black hole in milky way
A near-infrared image of a black hole at the center of the Milky Way galaxy as seen with Hubble Space Telescope/NICMOS. (NASA/STScI) (VOA)
  • Researches in Japan have discovered a super-massive black hole in Milky Way Galaxy
  • The black hole is believed to weigh as much as 400 suns
  • According to studies,  at least 100 million of these small black holes should exist in the Milky Way

Japan, September 5, 2017 : Astronomers have found new evidence for the existence of a mid-sized black hole, considered the missing link in the evolution of super-massive black holes.

Astronomers in Japan found the possible black hole in our own Milky Way galaxy, a long-theorized object which is bigger than the small black holes formed from a single star, but still much smaller than giant black holes such as the one at the center of the Milky Way.

Black holes are difficult to find because they do not emit any light. However, scientists can detect them by their influence on nearby objects.

The astronomers in Japan found new evidence of the so-called intermediate-mass black hole when they turned a powerful telescope in Chile’s Atacama desert on a gas cloud near the center of the Milky Way. The gases in the cloud move at unusual speeds, and the scientists believed they were being pulled by immense gravitational forces. They say the gravitational force is likely caused by a black hole measuring about 1.4 trillion kilometers across.

black hole in Milky way galaxy
Radio telescope antennas of the ALMA (Atacama Large Millimeter/submillimeter Array) project are seen in the Atacama desert, some 1500 km north of Santiago, Chile, VOA

The findings are published in the journal Nature Astronomy.

Theoretical studies predict at least 100 million of these small black holes should exist in the Milky Way, however only about 60 have been found.

The possible mid-sized black hole is much smaller than the super massive black hole that is located in the center of the galaxy, known as Sagittarius A, which weighs as much as 400 million suns.

“This is the first detection of an intermediate-mass black hole candidate in the Milky Way galaxy,” said the study’s leader, Tomoharu Oka from Keio University, Japan.

If confirmed, the intermediate-mass black hole could help explain how supermassive black holes operate. One theory is that supermassive black holes, which are at the center of most massive galaxies, are formed when smaller black holes steadily coalesce into larger ones. However, until now no definitive evidence has existed for intermediate-mass black holes that could indicate a middle step between the small and massive black holes already detected.

Researchers say they will continue to study the intermediate-mass black hole candidate in the hope of confirming its existence. (VOA)

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Super Earth? Planet Hunters Find Another ‘Earthy’ Planet in Our Galactic Neighborhood

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This planet is located in the liquid water habitable zone surrounding its host star, named LHS 1140. Credit: M. Weiss/CfA VOA

April 19, 2017: The hits, they just keep coming!

News was made in February when astronomers found seven potential earth-like planets orbiting the red dwarf star Trappist-1.

Wednesday, another red dwarf star is making headlines with the announcement of a ‘super earth’ found orbiting around the small red star LHS 1140.

Super Earth?

Artist’s impression of the super-Earth exoplanet LHS 1140b. Credit: ESO/spaceengine.org

VOA spoke with Jason Dittmann, from the Harvard-Smithsonian Center for Astrophysics, about the find.

He is the lead author of the paper laying out the new findings, which is being published Thursday in the journal Nature.

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He calls the planet a “Super Earth,” not because it’s any better than our blue-green sphere, but because it “is somewhere between the size of the Earth (the largest rocky planet in the Solar System) and Neptune. These planets are actually pretty common, but we don’t have any of them in our own Solar System so we don’t know much about them.”

Finding one is a big deal in general. But this one, dubbed LHS 1140b, is extra-special because it has turned up in the dwarf star’s habitable zone, that area in space where liquid water can exist on the surface.

The planet is 10 times closer to the star than Earth is to the sun, but red dwarfs are much smaller and much cooler than the giant inferno that keeps us warm.

The other special thing about this planet is that it’s about 5 billion years old, and according to Dittmann, “Five billion years should be more than enough time for life to develop [if it’s easy to develop, no one knows!] So this is definitely a good thing.”

Too close for comfort

In general, one big problem with the habitable planets scientists have found around red dwarfs — and this goes for a few of the seven they’ve found on Trappist-1 — and Proxima b, another found last year — is that they are so close to their star that the stellar radiation that is bombarding the planets can literally strip away any atmosphere.

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And this may be the case here.

But LHS 1140, according to team member Nicola Astudillo-Defru, “spins more slowly and emits less high-energy radiation than other similar low-mass stars.” That’s good news because the planet is so old and so big that chances are decent that it’s managed to hold onto an atmosphere.

Another bit of good news is that terrestrial planet LHS 1140b as seen from earth passes almost directly in front of its star, and that makes it a lot easier to do follow up research that Dittmann and his colleagues are already planning.
“We’re definitely already applying for as much telescope time as we can get our hands on,” Dittmann says, “to start looking at this planet’s atmosphere. And when the next generation of telescopes come online [The James Webb Space Telescope, and the ground-based Giant Magellan Telescope (GMT) and European-Extremely Large Telescope (EELT) ], we’ll be in a great spot to find out what sorts of atmospheres planets around M dwarfs have.”

The Webb telescope is expected to launch next year, but the Giant Magellan telescope won’t be online until 2025, and the EELT won’t be working until 2024.

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That’s a long time to wait, and undoubtedly there’ll be a long list of planets to explore by then. But the hope is that by studying the atmosphere of all these planets in the habitable zone, we might find some of the biological signatures of living things. Two of the European members of the team, Xavier Delfosse and Xavier Bonfils say that it’s the best candidate so far.

“The LHS 1140 system might prove to be an even more important target for the future characterization of planets in the habitable zone than Proxima b or TRAPPIST-1. This has been a remarkable year for exoplanet discoveries!” wrote Delfosse and Bonfils.

And there certainly will be more on the way. (VOA)

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NASA to launch balloon-borne Observatory to study Emissions from Cosmic material found between Stars

The observatory will help researchers map out parts of the Milky Way galaxy and a nearby galaxy known as the Large Magellanic Cloud

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Aerial View of NASA. Wikimedia

Washington, March 26, 2017: NASA has announced plans to launch a balloon-borne observatory to study the emissions from the cosmic material found between stars, known as the interstellar medium.

This data will help scientists determine the life cycle of interstellar gas in the Milky Way galaxy, witness the formation and destruction of star-forming clouds, and understand the dynamics and gas flow in the vicinity of the centre of our galaxy, the US space agency said in a statement on Saturday.

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The Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) mission will fly an Ultralong-Duration Balloon (ULDB) carrying a telescope with carbon, oxygen and nitrogen emission line detectors.

“GUSTO will provide the first complete study of all phases of the stellar life cycle, from the formation of molecular clouds, through star birth and evolution, to the formation of gas clouds and the re-initiation of the cycle,” said Paul Hertz of NASA’s Science Mission Directorate in Washington.

The mission, led by Christopher Walker of the University of Arizona, is targetted for launch in 2021 from McMurdo, Antarctica, and is expected to stay in the air between 100 to 170 days, depending on weather conditions, NASA said.

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This unique combination of data will provide the spectral and spatial resolution information needed for the researchers to untangle the complexities of the interstellar medium.

The observatory will help researchers map out parts of the Milky Way galaxy and a nearby galaxy known as the Large Magellanic Cloud.

“NASA has a great history of launching observatories in the Astrophysics Explorers Program with new and unique observational capabilities. GUSTO continues that tradition,” Hertz added. (IANS)