Main Menu

Drop Down MenusCSS Drop 

Down MenuPure CSS Dropdown Menu
Showing posts with label astrophysicist. Show all posts
Showing posts with label astrophysicist. Show all posts

Wednesday 22 July 2015

Dead galaxies in Coma Cluster may be packed with dark matter



New computer simulations show that these galaxies stopped star formation as early as 7 billion years ago but haven’t been ripped apart due to their dark matter.

Galaxies in a cluster roughly 300 million light-years from Earth could contain as much as 100 times more dark matter than visible matter, according to an Australian study.

The research used powerful computer simulations to study galaxies that have fallen into the Coma Cluster, one of the largest structures in the universe in which thousands of galaxies are bound together by gravity.

It found the galaxies could have fallen into the cluster as early as 7 billion years ago, which, if our current theories of galaxies evolution are correct, suggests they must have lots of dark matter protecting the visible matter from being ripped apart by the cluster.

Dark matter cannot be seen directly, but the mysterious substance is thought to make up about 84 percent of the matter in the universe.

Cameron Yozin from the University of Western Australia, who led the study, says the paper demonstrates for the first time that some galaxies that have fallen into the cluster could plausibly have as much as 100 times more dark matter than visible matter.

Yozin says the galaxies he studied in the Coma Cluster are about the same size as our Milky Way but contain only 1 percent of the stars.

He says the galaxies appear to have stopped making new stars when they first fell into the cluster between 7 and 10 billion years ago and have been dead ever since, leading astrophysicists to label them “failed” galaxies.

This end to star formation is known as “quenching.”

“Galaxies originally form when large clouds of hydrogen gas collapse and are converted to stars; if you remove that gas, the galaxy cannot grow further,” Yozin said.

“Falling into a cluster is one way in which this can happen. The immense gravitational force of the cluster pulls in the galaxy, but its gas is pushed out and essentially stolen by hot gas in the cluster itself.

“For the first time, my simulations have demonstrated that these galaxies could have been quenched by the cluster as early as 7 billion years ago.

“They have, however, avoided being ripped apart completely in this environment because they fell in with enough dark matter to protect their visible matter,” Yozin said.

Source : Astronomy Magzine

Thursday 16 July 2015

After the Moon and Mars, ISRO eyes Venus for next exploration mission

earth-2
After the successful launch of its Mars orbiter, the Indian Space Research Organisation (ISRO) is now viewing Venus as possibly the next planet it can study and explore.
“Besides the Mars-2 mission, we are looking at Venus and even an asteroid for exploration. A project has to be formulated for this before we chart out a proper roadmap for the explorations.  Venus is our neighbour and has many scientific challenges and aspects that need to be studied. Exploring an asteroid is also challenging task,” Dr Kiran Kumar, Isro chairman, told HT.
In 2014, India created history in space when its Mars orbiter slipped into the Red Planet’s orbit in its maiden attempt.
India became the first Asian country to reach Mars and the first in the world to enter the orbit of the planet in its first attempt.
isro-MOM-1200
Photo of Mars as taken by ISRO’s Mars Oriber Mission
Regarding the Saarc satellite, Dr Kumar said that it would be launched before December 2016. “The activities related to this project are in progress and we should begin building the satellite soon.”
Moving beyond satellite launches and planetary explorations, Isro is also aggressively working with many government departments on optimising the usage of space tools and data.
A national meet on space is likely to be held in Delhi next month, where ministries and departments of the government will give presentations on how they are using space tools in their workings. From civil aviation to railways, tribal affairs to health, postal to agriculture the number of government departments working with Isro has increased to more than 60 in the past few months.
Source : HindustanTimes

Saturday 15 November 2014

10 Wonders Of The Universe

Follow us on Google+ , Twitter and Facebook

What's the biggest thing in the universe? Find out here, along with 9 other incredible astronomical wonders.

http://www.youtube.com/watch?v=yUbQnHvXYEI

Friday 14 November 2014

3D-printed engine parts future of space launches: NASA

Follow us on Google+ , Twitter and Facebook

17104-nasa-logo

A team of NASA researchers has found that 3D manufactured copper parts could withstand the heat and pressure required of combustion engines used in space launches.

The US space agency and California-based rocket and missile propulsion manufacturer Aerojet Rocketdyne (AR) conducted 19 hot-fire tests on four injector and thrust chamber assembly configurations at NASA's Glenn Research Centre.

"The successful hot fire test of engine components provides confidence in the additive manufacturing process and paves the way for full-scale development," said Tyler Hickman, lead engineer for the test at Glenn.

3D printing approach is changing the speed, cost and flexibility of designing and building future machines for space and earth applications.

The work is a major milestone in the development and certification of different materials used in the manufacturing process.

Copper alloys offer unique challenges to the additive manufacturing processes.

"Additively manufactured metal propulsion components are truly a paradigm shift for the aerospace industry," added Paul Senick, Glenn project manager.

This will improve efficiency and bring down the cost of space launches and other earth applications, he concluded.

Source : business standard

A Universe of Blue Dots? --"Water Common During the Formation of All Planetary Systems"

Follow us on Google+ , Twitter and Facebook

pic-hyper-terra

The new SciFi blockbuster, Interstellar, shows astonauts from post apocalyptic earth, destroyed by what appears to be a modern dust-bowl, catapulted into the unknown of outer space in the hopes of finding a new home for the human race, only to discover an extraterrestrial tidal wave on a distant exo planet. How realistic is the premise of an alien water planet? New findings suggest it's based on solid science.
"This is an important step forward in our quest to find out if life exists on other planets," said Tim Harries, from the University of Exeter's Physics and Astronomy department, who was part of the research team. "We know that water is vital for the evolution of life on Earth, but it was possible that the Earth's water originated in the specific conditions of the early solar system, and that those circumstances might occur infrequently elsewhere. By identifying the ancient heritage of Earth's water, we can see that the way in which our solar system was formed will not be unique, and that exoplanets will form in environments with abundant water. Consequently, it raises the possibility that some exoplanets could house the right conditions, and water resources, for life to evolve."
The implication of these findings is that some of the solar system's water must have been inherited from the Sun's birth environment, and thus predate the Sun itself. If our solar system's formation was typical, this implies that water is a common ingredient during the formation of all planetary systems.

To date, the Kepler satellite has detected nearly 1,000 confirmed extrasolar planets. The widespread availability of water during the planet-formation process puts a promising outlook on the prevalence of life throughout the galaxy.

A pioneering new study has shown that water found on Earth predates the formation of the Sun – raising hopes that life could exist on exoplanets, the planets orbiting other stars in our galaxy. The ground-breaking research set out to discover the origin of the water that was deposited on the Earth as it formed.

It found that a significant fraction of water found on Earth, and across our solar system, predates the formation of the Sun. By showing that water is 'inherited' from the environment when a star is born, the international team of scientists believe other exoplanetary systems also had access to an abundance of water during their own formation.

As water is a key component for the development of life on Earth, the study has important implications for the potential for life elsewhere in the galaxy.

Scientists have previously been able to understand the conditions present when stars are formed by looking at the composition of comets and asteroids, which show which gases, dust and, most importantly, ices were circling the star at its birth.

The team of international scientists were able to use 'heavy water' ices – those with an excess of water made with the element deuterium rather than hydrogen – to determine whether the water ices formed before, or during, the solar system's formation.

Sunday 9 November 2014

Evidence of 'Starquakes' on Neutron Star

Follow us on Google+ , Twitter and Facebook

magnetar-flare1

An earthquake can be a pretty awe-inspiring natural event - a testament to the sheer power and size of shifting landmass. But what about seismic activity on a star? NASA's Fermi satellite recently spotted evidence of seismic waves rippling throughout a high-energy neutron star, resulting in an intense "storm" of high-energy blasts.

The star in question, called SGR J1550-5418, is a magnetar - an incredibly dense and highly magnetized neutron star that spins at an exceptionally high speed. The typical neutron star boasts a magnetic pull trillions of times stronger than the Earth's. A magnetar, by comparison, is about 1,000 times more magnetic than that.

Within the last four decades, only 23 magnetars in all have been identified, and among these stars, only three massive flares have ever been seen. The flares were related to "starquakes," in which instability of a neutron's pressing magnetic field literally shakes its surface.

"Fermi's Gamma-ray Burst Monitor (GBM) has captured the same evidence from smaller and much more frequent eruptions called bursts.

Source : nature world news

Saturday 8 November 2014

Is Earth the only technologically-intensive civilization in Universe?

Follow us on Google+ , Twitter and Facebook

Earth-With-Internet-Lights-Desktop-Wallpaper

A new study has revealed that the combination of earth-based science of sustainability and the space-oriented field of astrobiology can shed light on the future of technological civilization on Earth and is the planet first and only technologically-intensive culture in Universe.
Human-caused climate change, ocean acidification and species extinctions may eventually threaten the collapse of civilization, according to some scientists, while other people argue that for political or economic reasons industrial development should be allowed without restrictions.

In the paper, two astrophysicists argue that these questions may soon be resolvable scientifically, thanks to new data about the Earth and about other planets in our galaxy, and by combining the earth-based science of sustainability with the space-oriented field of astrobiology .

Astrophysicists Adam Frank and Woodruff Sullivan call for creation of a new research program to answer questions about humanity's future in the broadest astronomical context.

The authors explained that the point would be to see that Earth's current situation might, in some sense, be natural or at least a natural and generic consequence of certain evolutionary pathways.

The researchers also showed that how habitability studies of exoplanets hold important lessons for sustaining the civilization we have developed on Earth.

According to the results, studying past extinction events and using theoretical tools to model the future evolutionary trajectory of humankind and of still unknown but plausible alien civilizations could inform decisions that would lead to a sustainable future.

Source : Zee news

Hubble spots massive 'eye in the sky'

Follow us on Google+ , Twitter and Facebook

1415397667007_wps_8_p1444aw_jpg

It might look like a giant eye in the sky, or something from a science fiction fiction film, but in fact this incredible image reveals just how violent planet formation is.


Captured by the Hubble Space Telescope, it shows the huge dusty debris discs around stars.


Created by collisions between leftover objects from planet formation, were imaged around stars as young as 10 million years old and as mature as more than 1 billion years old in Nasa's images.


The researchers discovered that no two "disks" of material surrounding stars look the same.


“We find that the systems are not simply flat with uniform surfaces,” Schneider said.


Source: dailymail

Half of universe's stars are orphans with no galaxy

Follow us on Google+ , Twitter and Facebook

6975f540d86c9e34e1a457f4cf726735

Celestial orphans are relatively small, less massive, cooler than our sun, expert says

New observations from suborbital rocket launches and an orbiting observatory show that as many as half the stars in the universe may be orphans with no galaxy scientists said on Thursday. They found that the dim light these stars produce from the far reaches of the cosmos equals the amount coming from all the galaxies.
'The night sky on a planet around such a star would be profoundly boring and black to human eyes - no other stars, or at least very few, no Milky Way band, only distant galaxies.'                                        - Michael Zemcov, Caltech experimental astrophysicist

The phenomenon of the orphan star has been well known. Astronomers have witnessed tidal streams of stars being stripped away from colliding pairs of galaxies.




The data suggests orphan stars are probably relatively small, less massive and cooler than our Sun, but typical of most stars in the universe, said Caltech experimental astrophysicist Michael Zemcov.


The night sky as seen from Earth is brimming with starlight. But these orphans would be so distant from other stars that a view from one would offer almost complete nothingness.


"The night sky on a planet around such a star would be profoundly boring and black to human eyes - no other stars, or at least very few, no Milky Way band, only distant galaxies. You might be lucky and see your parent galaxy off in the distance like we see Andromeda," Zemcov said.


Zemcov said scientists have traced the origin of galaxies to about 13.2 billion years ago, 500 million years after the Big Bang that created the universe.


"Galaxies have been forming and interacting continuously since then, with a peak in the star formation rate about two billion years after the Big Bang," Zemcov said. "You have enough interactions over enough time, and you end up stripping out a lot of stars."




Source : cbc.ca

Thursday 6 November 2014

Rosetta spacecraft set to land on Comet Churyumov-Gerasimenko

Follow us on Google+ , Twitter and Facebook

1414642336467

An artist's impression of the Philae probe setting down on Comet Churyumov-Gerasimenko.

If you have an interest in space exploration, you could not have picked a better time in history to be alive than right now. Data and images stream back to Earth daily at an unprecedented rate from robotic spacecraft active at far-flung destinations all over the solar system. To use an old political quote – we've never had it so good.

In the past 50 years we've exploded out of our "little blue dot" to leave boot prints on the moon, land on Venus, Mars and Saturn's moon Titan, and to orbit Mercury, Jupiter, Saturn, asteroids and comets, giving us incredible visual vistas of all.

What's missing is a detailed view of dwarf planet Pluto, but we'll have that when the New Horizons spacecraft gets there next year.

There's also another missing first about to be achieved next week – we're going to make a soft landing on the surface of a comet.

Comet Churyumov-Gerasimenko had to wait around patiently for billions of years for humans to discover it in 1967. However, it's been a much shorter wait for an opportunity to get up close and personal with it – we're landing a probe on the frozen dumbbell-shaped comet next Wednesday, November 12.

The Rosetta spacecraft, carrying the Philae probe, was launched  from French Guiana in February 2004 by the European Space Agency. It arrived in August this year and has already given us great views of the comet.

It was named for the Rosetta Stone found in Egypt that was crucial in deciphering ancient Egyptian hieroglyphics. Similarly the "lander" is named for the Nile River island Philae, where an obelisk also assisted in solving the puzzle of these symbols.

Wednesday 5 November 2014

China probe flies around moon and back in first such mission since 1970s

Follow us on Google+ , Twitter and Facebook


img_5419

Chinese researchers examine the scorched Chang’e 5-T1 return capsule after it landed successfully in Inner Mongolia having travelled around the moon and back.

Photograph: Xinhua

China has completed its first return mission to the moon with the successful re-entry and landing on Earth of an unmanned probe, state media reported.

The probe, Chang’e 5-T1, landed safely in northern China’s Inner Mongolia region, state news agency Xinhua said, citing the Beijing Aerospace Control Centre.

Xinhua said the probe, dubbed “Xiaofei” (little flyer) on social media, took “some incredible pictures” of the Earth and the moon. It is the first trip around the moon and back since US and Russian flights of the 1970s, 40 years ago.

Prior to re-entering the Earth’s atmosphere the unnamed probe had been travelling at 11.2 kilometres per second (25,000 miles per hour), a speed that can generate temperatures of more than 1,500C (2,700F), the news agency reported.

To slow it down scientists let the craft “bounce” off Earth’s atmosphere before re-entering again and landing.

The probe’s mission was to travel to the moon, fly around it and head back to Earth, said the the state science and technology agency, Sastind. The module went 413,000km from Earth at its furthest point.

The mission was launched to test technology to be used in the Chang’e-5, China’s fourth lunar probe, which aims to gather and return samples from the surface in 2017.

The military-run space project has plans for a permanent orbiting station by 2020 and eventually to send a human to the moon.

China currently has a robotic rover, Yutu (Jade Rabbit), on the moon. It landed on 14 December 2013 and completed parts of its mission before grinding to a halt on 25 January 2014 due to equipment failure.

Source : The Guardian

Tuesday 4 November 2014

NASA rocket to click 1,500 images of Sun in 5 minutes

Follow us on Google+ , Twitter and Facebook


VBK-03-SOLAR_FLARE_2184508f

This image provided by NASA shows the sun emitting a significant X3.2-class flare erupting from the lower half of the sun, peaking at 5:40 p.m. EDT on Oct. 24, 2014. NASA's Solar Dynamics Observatory, which watches the sun constantly and captured images of the event.

A sounding rocket fitted with technology to gather 1,500 images of the Sun in flat five minutes is set for launch on Monday.


Capturing five images per second, the Rapid Acquisition Imaging Spectrograph Experiment (RAISE) mission will focus in on the split-second changes that occur near active regions on the Sun.


These are areas of intense and complex magnetic fields that can give birth to giant eruptions on the Sun that shoot energy and particles out in all directions, the U.S. space agency said in a statement.


“Even on a five-minute flight, there are niche areas of science we can focus on well. There are areas of the Sun that need to be examined with the high-cadence observations we can provide,” said Don Hassler, solar scientist at the Southwest Research Institute in Boulder, Colorado.


RAISE will create a kind of data product called a spectrogram which separates the light from the sun into different wavelengths.


“The Sun has been extremely active recently, producing several X-class flares in the past few weeks. The team will aim their instrument at one of these active regions to try to understand better the dynamics that cause these regions to erupt,” Mr. Hassler explained.


The team hopes to see how heat and energy move through such active regions, which, in turn, helps scientist understand what creates the regions and perhaps even what catalyses the sun’s eruptions.


RAISE’s launch time is planned for 2.07 p.m. (EST) from the White Sands Missile Range near Las Cruces, New Mexico.

Monday 3 November 2014

Success in the search for quiet, distant quasars

Follow us on Google+ and Facebook

1920x1080 Wallpaper

If quasars weren’t so luminous, we couldn’t see them so far away in space and time. But how about modest quasars, also far away? Astronomers say they’ve found some.

Astronomers at the Institute of Astrophysics of Andalusia (IAA-CSIC) in Spain say they have at last discovered a population of quiet, distant quasars. Nearly all the quasars we see at great distances are ultraluminous, and no wonder. They must be extremely luminous in order for us to glimpse them over the vastness of space. And yet astronomers have thought there must be, at those same vast distances, some quasars that were relatively quiet. Now, they say, they’ve found some and have been able to compare them both with the ultraluminous quasars in the early universe and also with closer quasars of moderate luminosity.

The farther away we look in space, the deeper we are looking into the past. Thus the ultraluminous quasars at great distances are showing us events taking place in the early universe: mergers of great galaxies containing gigantic black holes, with masses equivalent to billions of our suns, at their cores. These objects and events in the young universe are what we see as the distant quasars. The question has been, do the distant, tremendously high energy quasars have local relatives, in their same region of space and time, with much lower energy? And are those quiet quasars at great distances the dying versions of formerly ultraluminous quasars? Or are they something else entirely?

Jack W. Sulentic, astronomer at the Institute of Astrophysics of Andalusia (IAA-CSIC), who is leading the research, said:
Astronomers have always wanted to compare past and present, but it has been almost impossible because at great distances we can only see the brightest objects and nearby such objects no longer exist.

Until now we have compared very luminous distant quasars with weaker ones close by, which is tantamount to comparing household light bulbs with the lights in a football stadium.

Now, these astronomers say, they have detected the first distant, quiet quasars.

They say they employed the light-gathering power of the Gran Telescopio Canarias – known as GranTeCan or GTC telescope – located on the island of La Palma, in the Canary Islands in Spain. This telescope let Sulentic and his team obtain the first spectroscopic data from distant, low luminosity quasars similar to typical nearby ones.

They say their data are reliable enough to let them establish essential parameters of the quiet, distance quasars such as their chemical composition, and the mass of the central black hole or rate at which it absorbs surrounding gas and dust.

Quasars appear to evolve with distance. That is, the farther away they are in space, the brighter they are. This could indicate that quasars extinguish over time. Or it could be the result of anobservational bias masking a different reality: that gigantic quasars evolving very quickly, most of them already extinct, coexist with a quiet population that evolves more slowly, but which our technological limitations have not allowed astronomers to study. Ascensión del Olmo, another IAA-CSIC researcher who took part in this study, said:
We have been able to confirm that, indeed, apart from the highly energetic and rapidly evolving quasars, there is another population that evolves slowly. This population of quasars appears to follow the quasar main sequence … There does not even seem to be a strong relation between this type of quasars, which we see in our environment and those ‘monsters’ that started to glow more than 10 billion years ago.

Are there also differences between distant, quiet quasars and the moderate quasars closer to us in space? These astronomers say there are, and these differences are not surprising. Jack W. Sulentic said:
The local quasars present a higher proportion of heavy elements such as aluminum, iron or magnesium, than the distant relatives, which most likely reflects enrichment by the birth and death of successive generations of stars.

Bottom line: Astronomers in Spain have been able to identify a population of quiet quasars located in the distant universe, that is, in the early universe. They have compared them both to ultraluminous quasars in the early universe and also to quasars closer to us in space and time … and found differences in both cases.

Source : earth sky

NASA Releases Sounds From Space On SoundCloud

space-metal

NASA recently released over a half a century of sounds on SoundCloud, ranging from eerie noises from our solar system to historic moments in space exploration. The U.S. space agency recently created a SoundCloud page to reveal some of the most unusual sounds ever recorded, according to Mother Nature Network.

Although sounds in space are stifled by a vacuum, scientists have discovered ways of capturing noise using special instruments on the Voyager space probe that converts electromagnetic vibrations into sound, Gigwise reports.

The recordings include sounds of Saturn’s rings, Neptune, Jupiter, and Uranus, as well as what Earth would sound like millions of miles away. The files also contain sounds of shuttle launching and famous quotes from NASA astronauts.

Some of the sounds are quirky, chilling, and otherworldly. Here are seven of NASA’s most interesting uploads.

  1. “Earthsong” It is also called “Chorus” and is NASA’s most popular feed. The sound is produced by our own planet. It is described as an electromagnetic phenomenon caused by plasma waves in Earth’s radiation belts that hover 8,000 miles above the surface. The sound is too high for humans to hear, however ham radio operators have detected it for a long time, especially in the morning. It has been compared to the sound of birdsongs, from which the moniker is derived. NASA recorded this in 2012 with its EMFISIS probe.

  2. Saturn Radio” Saturn is home to dramatic auroras that are a lot like the northern and southern lights that dance around the Earth’s poles when solar wind hits the upper atmosphere. These lights are closely related to the planet’s strong radio emissions, first detected by the Cassini spacecraft 2002.

  3. “Interstellar Plasma” It has taken NASA’s Voyager 1 three decades since it left Earth to escape the sun’s magnetic field. This clip represents data that was recorded outside the heliosphere in 2012 and 2013. NASA calls it “The Sounds of Interstellar Space.”

  4. “Sonified Starlight” Scientists now may “sonify” non-auditory data by translating its values to noises, a lot like a Geiger counter converts silent radiation to audible clicks. Locating patterns in in data is often easier by ear, even if the data doesn’t represent sounds. The technique also helps scientists understand faraway stars, as with this clip of sonified light waves from KIC 7671081B, a variable star listed in NASA’s Kepler Input Catalog (KIC).

  5. Eerie Enceladus” This is Saturn’s sixth-largest of its several dozen moons. Enceladus spews enormous plumes of water vapor from its ice-covered surface. In 2005, the Cassini spacecraft detected a “significant atmosphere around it,” recording data from ion cyclotron waves.

  6. A Giant Leap” Neil Armstrong’s most famous words when his foot touched the surface of the moon. This was the first SoundCloud clip that NASA posted online.

  7. “Lift Off” These are the sounds of the first manned-mission to the moon, Apollo 11. The clip includes lift off, as well as the applause in the space center.





Some of NASA’s files might sound familiar to gamers.

NASA’s release of sounds from space on its SoundCloud page comprises of 63 files so far, including several of the most historic and mind-bending moments from the past 50 years of space exploration.
Source : inquisitr

Sunday 2 November 2014

Galaxies probably settled 2 billion years earlier than previously believed

Follow us on Google+

eso1143a

Scientists have dug deeper and discovered that galaxies actually settled in to their current forms some 2 billion years earlier than previously thought.

A group of researchers used the collective efforts of the hundreds of thousands of people that volunteered for the galaxy Zoo project to shed some light on the way that galaxies form and develop.

Dr. Brooke Simmons of the University of Oxford and her collaborators set Zoo volunteers the task of classifying the shapes of tens of thousands of galaxies observed by the Hubble Space Telescope. These objects are typically very distant, so they appeared more than 10 billion years ago, when the universe was about 3 billion years old, less than a quarter of its present age.

The newly classified galaxies were striking in that they look a lot like those in today's universe, with disks, bars and spiral arms. But theorists predict that they should have taken another 2 billion years to begin to form, so things seem to have been settling down a lot earlier than expected.

Brooke commented that they had predictions from galaxy simulations that they shouldn't find any of the barred features that we see in nearby, evolved galaxies, because very young galaxies might be too agitated for them to form. But with the public help they got in searching through many thousands of images of distant galaxies, they have discovered that some galaxies settle very early on in the universe.

The paper is published in Monthly Notices of the Royal Astronomical Society.

Source : Zee News

Saturday 1 November 2014

"Unexpected Planet" Discovered by Yale Astronomers

Follow us on Google+

6a00d8341bf7f753ef01b8d087f0f2970c-800wi

Astronomers have discovered a new planet that has a highly inconsistent orbit time around its Sun.

The low-mass, low-density planet, known only as PH3c, which is 2,300 light years away from the Earth, has an atmosphere loaded with hydrogen and helium.

The planet nearly escaped detection as PH3c does not have a consistent orbit time around its Sun due to the gravitational influence of other planets on its system.

“On the Earth, these effects are very small, only on the scale of one second or so,” said Joseph Schmitt, a graduate student at Yale University.

“PH3c’s orbital period changed by 10.5 hours in just 10 orbits,” explained Schmitt.

This inconsistency kept the planet out of reach for automated computer algorithms that search stellar light curves and identify regular dips caused by objects passing in front of stars, he said.

The researchers discovered the new planet with the help of Planet Hunters programme coordinated by Yale University and University of Oxford.

The programme, which has found over 60 planet candidates since 2010, enlists citizen scientists to check survey data from the Kepler spacecraft.

Not only did Planet Hunters spot PH3c, but the discovery also enabled astronomers to better characterise two other planets - one on each side of PH3c.

An outer planet PH3d is slightly larger and heavier than Saturn. An inner planet, PH3b may have a rocky composition like the Earth.

“Finding the middle planet was key to confirming the others and allowing us to find their masses,” Schmitt explained.

Universe may face a darker future

Artist’s impression of exocomets around Beta Pictoris

New research offers a novel insight into the nature of dark matter and dark energy and what the future of our Universe might be.

Researchers in Portsmouth and Rome have found hints that dark matter, the cosmic scaffolding on which our Universe is built, is being slowly erased, swallowed up by dark energy.

The findings appear in the journal Physical Review Letters, published by the American Physical Society. In the journal cosmologists at the Universities of Portsmouth and Rome, argue that the latest astronomical data favours a dark energy that grows as it interacts with dark matter, and this appears to be slowing the growth of structure in the cosmos.

Professor David Wands, Director of Portsmouth's Institute of Cosmology and Gravitation, is one of the research team.

He said: "This study is about the fundamental properties of space-time. On a cosmic scale, this is about our Universe and its fate.

"If the dark energy is growing and dark matter is evaporating we will end up with a big, empty, boring Universe with almost nothing in it.

"Dark matter provides a framework for structures to grow in the Universe. The galaxies we see are built on that scaffolding and what we are seeing here, in these findings, suggests that dark matter is evaporating, slowing that growth of structure."

Cosmology underwent a paradigm shift in 1998 when researchers announced that the rate at which the Universe was expanding was accelerating. The idea of a constant dark energy throughout space-time (the "cosmological constant") became the standard model of cosmology, but now the Portsmouth and Rome researchers believe they have found a better description, including energy transfer between dark energy and dark matter.

Research students Valentina Salvatelli and Najla Said from the University of Rome worked in Portsmouth with Dr Marco Bruni and Professor Wands, and with Professor Alessandro Melchiorri in Rome. They examined data from a number of astronomical surveys, including the Sloan Digital Sky Survey, and used the growth of structure revealed by these surveys to test different models of dark energy.
Professor Wands said: "Valentina and Najla spent several months here over the summer looking at the consequences of the latest observations. Much more data is available now than was available in 1998 and it appears that the standard model is no longer sufficient to describe all of the data. We think we've found a better model of dark energy.

"Since the late 1990s astronomers have been convinced that something is causing the expansion of our Universe to accelerate. The simplest explanation was that empty space – the vacuum – had an energy density that was a cosmological constant. However there is growing evidence that this simple model cannot explain the full range of astronomical data researchers now have access to; in particular the growth of cosmic structure, galaxies and clusters of galaxies, seems to be slower than expected."
Professor Dragan Huterer, of the University of Michigan, has read the research and said scientists need to take notice of the findings.

He said: "The paper does look very interesting. Any time there is a new development in the dark energy sector we need to take notice since so little is understood about it. I would not say, however, that I am surprised at the results, that they come out different than in the simplest model with no interactions. We've known for some months now that there is some problem in all data fitting perfectly to the standard simplest model."

Planet-forming lifeline discovered in a binary star system

GG Tauri-A

Artist’s impression of the double-star system GG Tauri-A.

If the feeding process into the system’s inner disk occurs elsewhere, the findings introduce many new potential locations to find exoplanets.

For the first time, researchers using ALMA have detected a streamer of gas flowing from a massive outer disk toward the inner reaches of a binary star system. This never-before-seen feature may be responsible for sustaining a second, smaller disk of planet-forming material that otherwise would have disappeared long ago. Half of Sun-like stars are born in binary systems, meaning that these findings will have major consequences for the hunt for exoplanets.

A research group led by Anne Dutrey from the Laboratory of Astrophysics of Bordeaux, France, used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the distribution of dust and gas in a multiple-star system called GG Tau-A. This object is only a few million years old and lies about 450 light-years from Earth in the constellation Taurus the Bull.

Like a wheel in a wheel, GG Tau-A contains a large, outer disk encircling the entire system as well as an inner disk around the main central star. This second inner disk has a mass roughly equivalent to that of Jupiter. Its presence has been an intriguing mystery for astronomers since it is losing material to its central star at a rate that should have depleted it long ago.

While observing these structures with ALMA, the team made the exciting discovery of gas clumps in the region between the two disks. The new observations suggest that material is being transferred from the outer to the inner disk, creating a sustaining lifeline between the two.

“Material flowing through the cavity was predicted by computer simulations but has not been imaged before. Detecting these clumps indicates that material is moving between the disks, allowing one to feed off the other,” said Dutrey. “These observations demonstrate that material from the outer disk can sustain the inner disk for a long time. This has major consequences for potential planet formation.”

Planets are born from the material left over from star birth. This is a slow process, meaning that an enduring disk is a prerequisite for planet formation. If the feeding process into the inner disk now seen with ALMA occurs in other multiple-star systems, the findings introduce a vast number of new potential locations to find exoplanets in the future.

The first phase of exoplanet searches was directed at single-host stars like the Sun. More recently, it has been shown that a large fraction of giant planets orbit binary-star systems. Now, researchers have begun to take an even closer look and investigate the possibility of planets orbiting the individual stars of multiple-star systems. The new discovery supports the possible existence of such planets, giving exoplanet discoverers new happy hunting grounds.

“Almost half the Sun-like stars were born in binary systems,” said Emmanuel Di Folco from the Laboratory of Astrophysics of Bordeaux, France. “This means that we have found a mechanism to sustain planet formation that applies to a significant number of stars in the Milky Way. Our observations are a big step forward in truly understanding planet formation.”ast

Thursday 30 October 2014

Czech Republic prepares own space program

1280px-Flag_of_the_Czech_Republic.svg

The Czech Republic will have its own space program, according to the National Space Plan for 2014-2019 that the government approved at the beginning of the week, the daily Hospodárske noviny (HN) writes today.
The plan recommends that the National Space Agency, "a considerably smaller variant of NASA," be established to integrate the currently fragmented competences in this field, HN says.
So far the Czech Republic has participated in the European Space Agency (ESA) programs, the second most significant player in space exploration after NASA, which they joined in 2008. Czechs annually give some 14 million euros to the ESA.
The national space exploration program should have an annual budget of three to five million euros and last for five years at least.
It should complement the research carried out within the ESA. Consequently, the National Space Agency could fund the projects that cannot be paid by the ESA, HN says.
Jan Kolář, head of the Czech Space Office NGO, welcomes the idea of the national space program.
"However, it should focus on the preparation of research and development activities in technical sciences," such as the development of materials and various types of detectors and the aerodynamics area, Kolář said.
HN writes that one of the rare successes that Czech science and industry has recently scored in this filed is a micro-accelerometer used in the SWARM satellites that were sent into space last November. The device, developed by 15 Czech firms, measures slight and slow accelerations that influence the satellite's movement, which removes possible distortions in the magnetic field measurements, HN notes.
However, the successful Czech micro-accelerometer was rather an exceptional case, Kolář told HN.
He said Czech participation in the ESA is limited by finances on the one hand, and by skills on the other hand. "In addition, our participation in each program is confronted with other European countries," he added.
Under the approved national space plan, the Czech Republic's contribution to the ESA's optional programs must be doubled at least, HN writes.
The transitory six-year period, in which the Czech Republic as a new ESA member could use a special incentive program, ends this year. Almost a half of the Czech obligatory payments to the agency went to it.
After the Czech Republic, Poland and Romania entered the ESA, while Estonia and Hungary plan to do so, and now they can use the advantages of newcomers, HN adds.
Source : prague post

Finnish researchers discover new type of black hole

Researchers at the University of Turku, in cooperation with international colleagues, have identified a new type of low-mass black hole. The type now discovered is a bright celestial object that emits x-rays.
black_hole_2-1920x1080

NOTE : It is not possible to directly observe a black hole, but it is possible to detect events in its vicinity. An artist's concept of x-ray emissions from a black hole, published by NASA, August 2014

This new type of black hole has less mass than other known types and is associated with x-ray emitting quasars.

Up until now, it has been assumed that the collapse of a massive star generally forms a massive black hole or a small neutron star. The mass gap between neutron stars and stellar mass black holes is a question that has been a matter of inquiry for numerous research teams.

The object now discovered and designed SWIFT J1753.5-0127 has a mass somewhere between that of a conventionally-recognized black hole and a neutron star. Previously, observed neutron stars have been found to have less than two solar masses, while black holes have over five.

Observations related to this new type of low-mass black hole were published in a paper by a group of reseachers at the University of Turku, the Osservatorio Astronomico di Padova, the Max-Planck-Institut für Astronomie, and the INAF-IASF Milan branch, and published by the Monthly Notices of the Royal Astronomical Society.

Source : yle