Archive for the ‘astronomy’ Category

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An enormous alien planet — one that is 11 times more massive than Jupiter — was discovered in the most distant orbit yet found around a single parent star.

The newfound exoplanet, dubbed HD 106906 b, dwarfs any planetary body in the solar system, and circles its star at a distance that is 650 times the average distance between the Earth and the sun. The existence of such a massive and distantly orbiting planet raises new questions about how these bizarre worlds are formed, the researchers said.

“This system is especially fascinating because no model of either planet or star formation fully explains what we see,” study lead researcher Vanessa Bailey, a fifth-year graduate student in the University of Arizona’s department of astronomy, said in a statement.

In the most commonly accepted theories of planet formation, it is thought that planets that orbit close to their parent star, such as Earth, began as small, asteroid-type bodies that clumped together in the primordial disk of gas and dust around the burgeoning star. Yet, this process operates too slowly to explain how giant planets form far away from their star, the researcher said.

Alternative hypotheses have suggested that distant giant planets may form in ways similar to mini binary star systems, Bailey said.

“A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit,” she explained.

In the HD 106906 system, the star and planet may have collapsed independently, but the materials that clumped together to form the planet were insufficient for it to grow large enough to ignite into a new star, Bailey said.

But, there are still problems with this scenario. For one, difference between the masses of two stars in a binary system is typically no more than a ratio of 10 to 1.

“In our case, the mass ratio is more than 100-to-1,” Bailey said. “This extreme mass ratio is not predicted from binary star formation theories — just like planet formation theory predicts that we cannot form planets so far from the host star.”

Researchers are also keen to study the new planet, because leftover material from when the planet and star formed can still be detected.

“Systems like this one, where we have additional information about the environment in which the planet resides, have the potential to help us disentangle the various formation models,” Bailey said. “Future observations of the planet’s orbital motion and the primary star’s debris disk may help answer that question.”

The planet HD 106906 b is only 13 million years old, and is still glowing from the residual heat from its formation,” the researchers said. By comparison, Earth formed 4.5 billion years ago, which makes it roughly 350 times older than the newfound exoplanet.

The planet was found using a thermal infrared camera mounted on the Magellan telescope in the Atacama Desert in Chile. The researchers used data from the Hubble Space Telescope to confirm their discovery.

The study, which has been accepted for publication in a future issue of The Astrophysical Journal Letters, could lead to a better understanding of distantly orbiting exoplanets.

“Every new directly detected planet pushes our understanding of how and where planets can form,” study co-investigator Tiffany Meshkat, a graduate student at Leiden Observatory in the Netherlands, said in a statement. “Discoveries like HD 106906 b provide us with a deeper understanding of the diversity of other planetary systems.”

http://www.nbcnews.com/science/enormous-alien-planet-discovered-most-distant-orbit-ever-seen-2D11703497

Thanks to Dr. D for bringing this to the attention of the It’s Interesting community.

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Pluto’s orbit may host a formation of 10 or more tiny undiscovered moons, which would each measure just 1 to 3 kilometres across, astronomers say.

This preliminary finding could make life even more difficult for the team planning NASA’s New Horizons mission, which is slated to take the first-ever up-close look at the Pluto system in July 2015.

After Pluto’s fifth known moon, a small satellite known as P5, was discovered last year, officials said they may need to redraw the spacecraft’s path to avoid such obstacles.

In the new study, astronomers led by Scott Kenyon of the Harvard-Smithsonian Center for Astrophysics used computer simulations that treat smaller particles statistically.

Once objects get above a certain size, roughly 1 km across, then the programme renders them individually – and this is when the satellites pop up.

It’s hard to say how many there are, the researchers said, as it’s difficult to simulate collisions among these tiny satellites. There could be anywhere from one to more than 10 objects lurking beyond Hydra’s orbit.

While the team can simulate these satellites, they said it’s unlikely they could be spotted, if they exist, from Earth.

The brightness of the potential objects dance with the edge of the Hubble Space Telescope’s capabilities, Kenyon said, and they are likely beyond the reach of even the most sensitive ground-based telescopes, such as the Keck Observatory in Hawaii.

New Horizons might be able to spot smaller satellites before it gets there, but Kenyon said he wasn’t sure when the objects would appear big enough for the spacecraft to detect.

The satellites would be “easily visible” during the spacecraft’s closest approach to Pluto in 2015, researchers said.

The study was submitted for publication in The Astronomical Journal.

http://www.phenomenica.com/2013/03/pluto-may-have-10-more-undiscovered-moons.html

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Astronomers have discovered the largest known structure in the universe – a group of quasars so large it would take 4 billion years to cross it while traveling at speed of light.

The immense scale also challenges Albert Einstein’s Cosmological Principle, the assumption that the universe looks the same from every point of view, researchers said.

The findings by academics from Britain’s University of Central Lancashire were published in the journal Monthly Notices of the Royal Astronomical Society and reported on the society’s website on Friday.

Quasars are believed to be the brightest objects in the universe, with light emanating from the nuclei of galaxies from the early days of the universe and visible billions of light-years away.

“Since 1982 it has been known that quasars tend to group together in clumps or ‘structures’ of surprisingly large sizes, forming large quasar groups or LQGs,” the society said.

This newly discovered large quasar group has a dimension of 500 megaparsecs, each megaparsec measuring 3.3 million light-years.

Because the LQG is elongated, its longest dimension is 1,200 megaparsecs, or 4 billion light-years, the society said.

That size is 1,600 times larger than the distance from Earth’s Milky Way to the nearest galaxy, the Andromeda.

“While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe,” Roger Clowes, leader of the research team, said in a statement. “This is hugely exciting – not least because it runs counter to our current understanding of the scale of the universe.”

Clowes said the team would continue to investigate the phenomenon with particular interest in the challenge to the Cosmological Principle, which has been widely accepted since Einstein, whose work still forms the basis for much of modern cosmology.

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

http://www.reuters.com/article/2013/01/12/space-quasars-idUSL1E9CC08B20130112

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An international team of astronomers led by the University of Hertfordshire has discovered that Tau Ceti, one of the closest and most Sun-like stars, may host five planets — with one in the star’s habitable zone.

At a distance of twelve light years and visible with the naked eye in the evening sky, Tau Ceti is the closest single star that has the same spectral classification as our Sun. Its five planets are estimated to have masses between two and six times the mass of Earth — making it the lowest-mass planetary system yet detected. One of the planets lies in the habitable zone of the star and has a mass around five times that of Earth, making it the smallest planet found to be orbiting in the habitable zone of any Sun-like star.

The international team of astronomers, from the UK, Chile, the USA, and Australia, combined more than six-thousand observations from three different instruments and intensively modelled the data. Using new techniques, the team has found a method to detect signals half the size previously thought possible. This greatly improves the sensitivity of searches for small planets and suggests that Tau Ceti is not a lone star but has a planetary system.

Mikko Tuomi, from the University of Hertfordshire and the first author of the paper, said: “We pioneered new data modelling techniques by adding artificial signals to the data and testing our recovery of the signals with a variety of different approaches. This significantly improved our noise modelling techniques and increased our ability to find low mass planets.”

“We chose Tau Ceti for this noise modelling study because we had thought it contained no signals. And as it is so bright and similar to our Sun it is an ideal benchmark system to test out our methods for the detection of small planets,” commented Hugh Jones from the University of Hertfordshire.

James Jenkins, Universidad de Chile and Visiting Fellow at the University of Hertfordshire, explained: “Tau Ceti is one of our nearest cosmic neighbours and so bright that we may be able to study the atmospheres of these planets in the not too distant future. Planetary systems found around nearby stars close to our Sun indicate that these systems are common in our Milky Way galaxy.”

Over 800 planets have been discovered orbiting other worlds, but planets in orbit around the nearest Sun-like stars are particularly valuable. Steve Vogt from University of California Santa Cruz said: “This discovery is in keeping with our emerging view that virtually every star has planets, and that the galaxy must have many such potentially habitable Earth-sized planets. They are everywhere, even right next door! We are now beginning to understand that Nature seems to overwhelmingly prefer systems that have a multiple planets with orbits of less than one hundred days. This is quite unlike our own solar system where there is nothing with an orbit inside that of Mercury. So our solar system is, in some sense, a bit of a freak and not the most typical kind of system that Nature cooks up.”

“As we stare the night sky, it is worth contemplating that there may well be more planets out there than there are stars … some fraction of which may well be habitable,” remarked Chris Tinney from the University of New South Wales.

Journal Reference:

1.M. Tuomi, H. R. A. Jones, J. S. Jenkins, C. G. Tinney, R. P. Butler, S. S. Vogt, J. R. Barnes, R. A. Wittenmyer, S. O’Toole, J. Horner, J. Bailey, B. D. Carter, D. J. Wright, G. S. Salter, D. Pinfield. Signals embedded in the radial velocity noise. Periodic variations in the tau Ceti velocities. Astronomy & Astrophysics, 2012; DOI: 10.1051/0004-6361/201220509

http://www.sciencedaily.com/releases/2012/12/121219084102.htm

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Like a ship plowing through still waters, the giant star Zeta Ophiuchi is speeding through space, making waves in the dust ahead. NASA’s Spitzer Space Telescope has captured a dramatic, infrared portrait of these glowing waves, also known as a bow shock.

Astronomers theorize that this star was once sitting pretty next to a companion star even heftier than itself. But when that star died in a fiery explosion, Zeta Ophiuchi was kicked away and sent flying. Zeta Ophiuchi, which is 20 times more massive and 80,000 times brighter than our sun, is racing along at about 54,000 mph (24 kilometers per second).

In this view, infrared light that we can’t see with our eyes has been assigned visible colors. Zeta Ophiuchi appears as the bright blue star at center. As it charges through the dust, which appears green, fierce stellar winds push the material into waves. Where the waves are the most compressed, and the warmest, they appear red. This bow shock is analogous to the ripples that precede the bow of a ship as it moves through the water, or the pileup of air ahead of a supersonic airplane that results in a sonic boom.

NASA’s Wide-field Infrared Survey Explorer, or WISE, released a similar picture of the same object in 2011. WISE sees infrared light as does Spitzer, but WISE was an all-sky survey designed to take snapshots of the entire sky. Spitzer, by contrast, observes less of the sky, but in more detail. The WISE image can be seen at: http://www.jpl.nasa.gov/news/news.php?release=2011-026 .

NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit: http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .

http://www.sciencedaily.com/releases/2012/12/121218153330.htm

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Astronomers have discovered what may be the most massive black hole ever known in a small galaxy about 250 million light-years from Earth, scientists say.

The supermassive black hole has a mass equivalent to 17 billion suns and is located inside the galaxy NGC 1277 in the constellation Perseus. It makes up about 14 percent of its host galaxy’s mass, compared with the 0.1 percent a normal black hole would represent, scientists said.

“This is a really oddball galaxy,” said study team member Karl Gebhardt of the University of Texas at Austin in a statement. “It’s almost all black hole. This could be the first object in a new class of galaxy-black hole systems.”

The giant black hole is about 11 times as wide as the orbit of Neptune around our sun, researchers said. The mass is so far above normal that the scientists took a year to double-check and submit their research paper for publication, according to the study’s lead author, Remco van den Bosch.

“The first time I calculated it, I thought I must have done something wrong. We tried it again with the same instrument, then a different instrument,” van den Bosch, an astronomer at Germany’s Max Planck Institute for Astronomy, told SPACE.com. “Then I thought, ‘Maybe something else is happening.'” [Strangest Black Holes in the Universe]

The finding may have implications for our understanding of how giant black holesevolve  in the center of galaxies.

Astronomers typically believe that the size of the central part of a galaxy, and the black hole inside of it, are linked. But the vastly different proportions seen in NGC 1277 are calling that into question.

NGC 1277’s black hole could be many times more massive than its largest known competitor, which is estimated but not confirmed to be between 6 billion and 37 billion solar masses in size.It makes up about 59 percent of its host galaxy’s central mass – the bulge of stars at the core. The object’s closest competitor is in the galaxy NGC 4486B, whose black hole takes up 11 percent of that galaxy’s central bulge mass.  

 However, van den Bosch’s team says it has also spotted five other galaxies near NGC 1277 that look about the same, and may also harbor gigantic black holes inside of them.

“You always expect to find one sort [of a phenomenon], but now we have six of them,” van den Bosch said. “We didn’t expect them, because we do expect the black holes and the galaxies to influence each other.”

The research is detailed in the Nov. 29 edition of the journal Nature.

http://www.livescience.com/25101-biggest-black-hole-discovery.html

 

Alien life beyond our solar system could be discovered within the next 40 years, a top British astronomer has said.

According to Lord Martin Rees, the president of the Royal Society of London, developments in astronomy mean that astrophysicists could be able to view images of distant planets outside of our solar system as soon as 2025, and potentially discover whether there is some form of life on them, the Daily Mail reported.

The question of whether earth is alone in supporting living organisms has puzzled scientists, philosophers for centuries.

“We know now that stars are orbited by retinues of planets just as our sun is. We have learned this in just the last decade, essentially,” Rees said.

“Within 10 or 20 years we will be able to image other planets like the earth, orbiting other stars. That will be a really exciting subject to see if there is evidence for [extra-terrestrial] life or not,” Rees was quoted as saying by the paper.

Speaking at a debate on the meaning of life for the launch of Professor Stephen Hawking’s new show Grand Design, he added that finding out more about the “origin of life, the place where it exists, and whether aliens exist, is going to be crucial over the next four decades”.

“There may be some questions that our brains will never understand, in the same way that chimpanzees couldn’t understand quantum theory, that are just beyond human brains,” Rees added.

Last year Lord Rees said it was possible that aliens were “staring us in the face” in a form humans are unable to recognise.

“I suspect there could be life and intelligence out there in forms we can’t conceive,” he added.

http://www.phenomenica.com/2012/09/aliens-could-be-discovered-within-40-years.html