‘Star With 3 Super-Earth Exoplanets Just 21 Light Years Away’


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Astronomers said Thursday they had found a planetary system with three super-Earths orbiting a bright, dwarf star one of them likely a volcanic world of molten rock.
The four-planet system had been hiding out in the M-shaped, northern hemisphere constellation Cassiopeia, “just” 21 light years from Earth, a team reported in the journal Astronomy & Astrophysics.

It comprises four planets one giant and three super-Earths orbiting a star dubbed HD219134.

Super-Earths have a mass higher than Earth’s but are lighter than gas giants like Neptune, Saturn or Jupiter. They can be made of gas, rock, or both.

The planet with the shortest orbit, HD219134b, zips around every three days, and has now been observed transiting across the face of its star as seen from the vantage point of Earth.

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Measurements from the ground and with Nasa’s Spitzer space telescope showed its mass was 4.5 times higher than Earth’s, and that it was 1.6 times larger.

“Its mean density is close to the density of Earth, suggesting a possibly similar composition as well,” said a press statement from the University of Geneva, whose astronomers took part in the research.

“It’s very close to the star. The temperature is about 700 degrees” Kelvin (427 Celsius, 800 Fahrenheit), study co-author Stephane Udry told AFP.

“Probably the surface is melting… kind of a melted lava world with volcanoes… not good for life.”

It was not in the so-called “habitable zone” of its star, and would not have liquid water necessary for life.

But HD219134b is exciting for another reason: it is the closest transiting planet known to scientists, and thus offers a rare opportunity for further study of its composition and atmosphere against the backdrop of its star.

“These transiting systems are especially interesting in that they allow characterisation of the atmosphere of the planet (by studying) the light of the star going through the atmosphere,” Udry said.

And the system is relatively near at a distance of 21 light years from Earth. By comparison, the closest star to our Sun is three light years away, and the second six light years.

Among HD219134b’s fellow planets, the second furthest from the star weighs 2.7 times as much as Earth and orbits in 6.8 days, the next is 8.7 times more massive than Earth with a 47-day orbit.

A giant planet further out orbits once every three years, the team said.

Source : NDTV

Astronomers Find Rare 5-Star System


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An illustration of two contacting stars — part of the newly discovered bizarre five-star system.

Scientists have discovered an absolutely bizarre star system about 250 light years away, in the constellation Ursa Major.

The system (officially known as 1SWASP J093010.78+533859.5) features five stars that are all gravitationally bound together. Two orbit each other in what’s called a contact eclipsing binary, meaning they’re so close together that they actually share an atmosphere, with gases flowing between them.

Another two stars also orbit each other, but at a much greater distance — about 1.8 million miles, which is more than twice the diameter of the sun. Another star hangs out near that pair, but doesn’t appear to orbit them.

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Systems that include five stars gravitationally bound together are rare, though not unprecedented (astronomers have actually found systems that include as many as six stars). But this is the first one ever found that includes multiple pairs of stars orbiting each other.

The discoverers of the strange system — a team of astronomers from Open University in the UK and elsewhere — presented all these discoveries in a new paper published in the journal Astronomy & Astrophysics. Thanks to George Dvorsky at io9 for bringing it to our attention.

Source: vox.com

[VIDEO] If some celestial bodies were closer to us


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For 25 years now, the Hubble Space Telescope (and many other satellites) has stimulated us with numerous jaw dropping images of space—stretching from the Great Nebula of Orion, to the Whirlpool Galaxy. They all look so huge and comprehensive, you can nearly imagine yourself moving through space, looking directly at them from up close—yet even the closest among them are unfathomably far away (the closest planet is nearly 162 million miles/261 million kilometers from sun, while the closest star is over 4 light-years distant). In a recent video, the Russian Space Agency (Roscosmos, to be exact) visualizes how our sky may look if some of these marvels were in nearer proximity to Earth. Watch the video below:

Hubble Space Telescope turns 25 and Here are some of the Most Amazing Pictures Taken by it


Hubble Space Telescope marks 25th anniversary in orbit this week. So, There are some  best images taken by Hubble Space Telescope during its 25 years journey. These Images are 100% real and contains no CGI

Hubble has traveled 3.4 billion miles, circling Earth nearly 137,000 times and making more than 1.2 million observations of more than 38,000 celestial objects, according to the Space Telescope Science Institute in Baltimore. The most distant objects spotted by Hubble — primitive galaxies — are some 13 billion light-years away and date to within 400 million or so years of the universe’s origin, known as the Big Bang.

Hubble provides an average of 829 gigabytes of archival data every month, according to the institute. Altogether, Hubble has produced more than 100 terabytes of data.

Some of the images have description about it. if anyone wants to read image description just click that image. and  Enjoy……

Image Credit : hubblesite.org

Source:Fox news

Our star is five billion years younger than most in the Milky Way


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Our sun is nearly 4.5 billion years — which means it missed the charming initial years of the Milky Way galaxy. If you were standing on a planet nearly about 10 billion years ago, when the Milky Way was pretty young, the night sky would have appeared very different. The image below is an artist’s impression of the night sky on a planet in a relatively young Milky Way-type galaxy, the way our galaxy was 10 billion years ago. You can see “the sky are ablaze with star birth. Pink clouds of gas harbor newborn stars, and bluish-white, young star clusters litter the landscape,” as NASA explains.

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Image Credit: NASA/ESA/Z. Levay (STScI)

A recent study of young galaxies like our own demonstrates that as these galaxies slow down creating stars, they also stop developing as quickly in general. Which is quite logical. NASA explains:

“Astronomers don’t have baby pictures of our Milky Way’s formative years to trace the history of stellar growth so they studied galaxies similar in mass to our Milky Way, found in deep surveys of the universe. The farther into the universe astronomers look, the further back in time they are seeing, because starlight from long ago is just arriving at Earth now. From those surveys, stretching back in time more than 10 billion years, researchers assembled an album of images containing nearly 2,000 snapshots of Milky Way-like galaxies. The new census provides the most complete picture yet of how galaxies like the Milky Way grew over the past 10 billion years into today’s majestic spiral galaxies. The multi-wavelength study spans ultraviolet to far-infrared light, combining observations from NASA’s Hubble and Spitzer space telescopes, the European Space Agency’s Herschel Space Observatory, and ground-based telescopes, including the Magellan Baade Telescope at the Las Campanas Observatory in Chile.”

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Above is a selection of Hubble Space Telescope photos, displaying how galaxies similar to our own developed over time.

Source : Physics-astronomy

[Video] Space’s 10 Most Gigantic Disasters


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Here are the 10 Most Biggest Explosions and Impacts Ever Known in Space.

Enjoy the video…

Source : Hybrid Librarian (Video Uploader)

Hubble Space Telescope Views Globular Cluster Messier 22


The crammed centre of Messier 22

This newly released Hubble image shows Messier 22, the brightest globular cluster visible from the northern hemisphere.

A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers.

Messier 22 is located in the constellation Sagittarius, approximately 10,400 light-years away.

It was the first globular cluster to be discovered. German astronomer Johann Abraham Ihle found it on August 26, 1665, while observing Saturn.

The cluster, also known as M22 or NGC 6656, has a diameter of about 70 light-years and half a million solar masses.

According to astronomers, Messier 22 orbits the galactic center once every 200 million years.

The cluster is an easy object for the naked eye to see. Despite its relative proximity to us, the light from the cluster’s stars is not as bright as it should be as it is dimmed by dust and gas located between us and Messier 22.

As they are leftovers from the early Universe, globular clusters are popular study objects for astronomers.

Messier 22 has fascinating additional features: six planet-sized objects that are not orbiting a star have been detected in the cluster; it seems to host two black holes.

The cluster is one of only three ever found to host a planetary nebula – a short-lived gaseous shells ejected by massive stars at the ends of their lives.

Source : Sci-news

Black Hole 12 Billion Times Bigger Than the Sun Discovered


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Scientists say they have discovered a black hole so big that it challenges the theory about how they grow.

The scientists were initially reluctant to classify it as a black hole because it was too bright, its luminosity equal to the brightness of 420 trillion suns. Most of the people do not believe black holes to be bright, though they can be. This is particularly so because black holes suck everything inside them but just before that there is tremendous friction which produces a lot of light.

Scientists said this black hole was formed about 900 million years after the Big Bang.

But with measurements indicating it is 12 billion times the size of the Sun, the black hole challenges a widely accepted hypothesis of growth rates.

“Based on previous research, this is the largest black hole found for that period of time,” Dr Fuyan Bian, Research School of Astronomy and Astrophysics, Australian National University (ANU).

“Current theory is for a limit to how fast a black hole can grow, but this black hole is too large for that theory.”

The creation of supermassive black holes remains an open topic of research. However, many scientists have long believed the growth rate of black holes was limited.

Black holes grow, scientific theory suggests, as they absorb mass. However, as mass is absorbed, it will be heated creating radiation pressure, which pushes the mass away from the black hole.

“Basically, you have two forces balanced together which sets up a limit for growth, which is much smaller than what we found,” said Bian.

The black hole was discovered a team of global scientists led by Xue-Bing Wu at Peking University, China, as part of the Sloan Digital Sky Survey, which provided imagery data of 35 percent of the northern hemisphere sky.

The ANU is leading a comparable project, known as SkyMapper, to carry out observations of the Southern Hemisphere sky.

Bian expects more black holes to be observed as the project advances.

Source : Reuters , ScienceTimes

New 3D Map of Supernova Cassiopeia A Reveals Bubbly Interior


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Scientists have taken a closer look at one of the most well studied supernova remnants in our galaxy, Cassiopeia A. They’ve created a new 3D map of its interior that reveals surprising, never-before-seen details about the supernova. A photograph of Cas A from NASA’s Chandra X-ray Observatory reveals the supernova remnant’s complex structure. (Photo : NASA/CXC/SAO)

Scientists have taken a closer look at one of the most well studied supernova remnants in our galaxy, Cassiopeia A. They’ve created a new 3D map of its interior that reveals surprising, never-before-seen details about the supernova.

Cassiopeia A, or Cas A, was first created about 340 years ago. That’s when a massive star exploded in the constellation Cassiopeia. The extremely hot and radioactive material that streamed outward from the stars core mixed and churned outer debris, creating a supernova remnant.

That said, examining the complex physics behind these explosions is difficult to model. That’s why researchers have carefully studied relatively young supernova remnants like Cas A to investigate key processes that drive these stellar explosions.

To create the new 3D map, the researchers examined Cas A in near-infrared wavelengths of light using the Mayall 4-meter telescope in Arizone. Then, spectroscopy gave them the expansion velocities of extremely faint material in Cas A’s interior, which provided them with the third dimension.

“We’re sort of like bomb squad investigators,” said Dan Milisavljevic, one of the researchers, in a news release. “We examine the debris to learn what blew up and how it blew up. Our study represents a major step forward in our understanding of how stars actually explode.”

The new 3D map reveals bubble-like cavities within the exploded star. These cavities were likely created by plumes of radioactive nickel generated during the stellar explosion. Since the nickel will decay to form iron, it’s likely that Cas A’s interior bubbles will be enriched with as much as a tenth of a solar mass of iron.

The findings reveal a bit more about the interiors of supernovae. This, in turn, may help inform future studies of these exploded stars.

The findings are published in the journal Science.

Source : Scienceworldreport

Scientists Discover Exoplanet With Rings Far More Impressive Than Our Saturn


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Artist’s conception of the extrasolar ring system circling the young giant planet or brown dwarf J1407b is shown. Credit: Ron Miller

Children and adults alike marvel at the rings around Saturn. In a model of our solar system, Saturn—and its rings—is typically the one that gets the most attention.

But while it is easy to be fascinated by Saturn, astronomers have recently found an exoplanet with an even grander expanse of wings that is sure to wow a new generation of stargazers.

“The star is much too far away to observe the rings directly, but we could make a detailed mode based on the rapid brightness variations in the star light passing through the ring system. If we could replace Saturn’s rings with the rings around J1407b, they would be easily visible at night and be many times larger than the full moon,” explains lead researcher Matthew Kenworthy. “The details that we see in the light curve are incredible. The eclipse lasted for several weeks, but you see rapid changes on time scales of tens of minutes as a result of fine structures in the rings.”

Study co-author Eric Mamaek, who first found the rings of the planet, comments, “The planetary science community has theorized for decades that planets like Jupiter and Saturn would have had, at an early stage, disks around them that then led to the formation of satellites. However, until we discovered this object in 2012, no-one had seen such a ring system. This is the first snapshot of satellite formation on million-kilometer scales around a substellar object.”

The University of Rochester professor of physics and astronomy goes on to say, “This planet is much larger than Jupiter or Saturn, and its ring system is roughly 200 times larger than Saturn’s rings are today. You could think of it as a kind of super Saturn.”

Source : piercepioneer.com