Discovery of a Pulsar and Supermassive Black Hole Pairing Could Help Unlock the Enigma of Gravity


Last year, the very rare presence of a pulsar (named SGR J1745-2900) was also detected in the proximity of a supermassive black hole (Sgr A**, made up of millions of solar masses), but there is a combination that is still yet to be discovered: that of a pulsar orbiting a ‘normal’ black hole; that is, one with a similar mass to that of stars.

The intermittent light emitted by pulsars, the most precise timekeepers in the universe, allows scientists to verify Einstein’s theory of relativity, especially when these objects are paired up with another neutron star or white dwarf that interferes with their gravity. However, this theory could be analysed much more effectively if a pulsar with a black hole were found, except in two particular cases, according to researchers from Spain and India.

Pulsars are very dense neutron stars that are the size of a city (their radius approaches ten kilometres), which, like lighthouses for the universe, emit gamma radiation beams or X-rays when they rotate up to hundreds of times per second. These characteristics make them ideal for testing the validity of the theory of general relativity, published by Einstein between 1915 and 1916.

“Pulsars act as very precise timekeepers, such that any deviation in their pulses can be detected,” Diego F. Torres, ICREA researcher from the Institute of Space Sciences (IEEC-CSIC), explains to SINC. “If we compare the actual measurements with the corrections to the model that we have to use in order for the predictions to be correct, we can set limits or directly detect the deviation from the base theory.”

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These deviations can occur if there is a massive object close to the pulsar, such as another neutron star or a white dwarf. A white dwarf can be defined as the stellar remnant left when stars such as our Sun use up all of their nuclear fuel. The binary systems, comprised of a pulsar and a neutron star (including double pulsar systems) or a white dwarf, have been very successfully used to verify the theory of gravity.

Until now scientists had considered the strange pulsar/black hole pairing to be an authentic ‘holy grail’ for examining gravity, but there exist at least two cases where other pairings can be more effective. This is what is stated in the study that Torres and the physicist Manjari Bagchi, from the International Centre of Theoretical Sciences (India) and now postdoc at the IEEC-CSIC, have published in the Journal of Cosmology and Astroparticle Physics. The work also received an Honourable Mention in the 2014 Essays of Gravitation prize.

The first case occurs when the so-called principle of strong equivalence is violated. This principle of the theory of relativity indicates that the gravitational movement of a body that we test only depends on its position in space-time and not on what it is made up of, which means that the result of any experiment in a free fall laboratory is independent of the speed of the laboratory and where it is found in space and time.

The other possibility is if one considers a potential variation in the gravitational constant that determines the intensity of the gravitational pull between bodies. Its value is G = 6.67384(80) x 10-11 N m2/kg2. Despite it being a constant, it is one of those that is known with the least accuracy, with a precision of only one in 10,000.

In these two specific cases, the pulsar-black hole combination would not be the perfect ‘holy grail’, but in any case scientists are anxious to find this pair, because it could be used to analyse the majority of deviations. In fact, it is one of the desired objectives of X-ray and gamma ray space telescopes (such as Chandra, NuStar or Swift), as well as that of large radio telescopes that are currently being built, such as the enormous ‘Square Kilometre Array’ (SKA) in Australia and South Africa.

Source : Daily galaxy

Ground-Based Telescope Observes Exoplanet Transiting Bright Star


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 Graphical representation of an Exoplanet (Click Image to Download)

For the first time, an international team of astronomers has used a ground-based telescope to detect and observe the transit of a planet in front of a Sun-like star outside of our own solar system.

Until now, only space-based telescopes were capable of detecting the transits of exoplanets as they passed by bright stars.

Distortions caused by the atmosphere , the same phenomenon that makes stars look like they’re twinkling, makes it difficult for astronomers to observe transiting planets around bright stars from telescopes based on Earth.

In September, 2013, Japanese astronomers, using the ground-based Subaru telescope were able to observe the transit of super-Earth, GJ 1214b , but this exoplanet orbits a much dimmer star, known as a red dwarf.

According to team leader, Dr. Ernst de Mooij  of Queen’s University Belfast  in Northern Ireland, 55 Cancri e, was measured to have a diameter of about 26,000 km, which is twice that of Earth, but with eight times its mass.

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This artist’s conception shows the super-Earth 55 Cancri e (right) compared to the Earth (left). (NASA/JPL) (Click Image to Download)

The most recent achievement involves a super-sized Earth-like planet in a binary star system more than 40-light years away. Called 55 Cancri e , the planet orbits its primary star 55 Cancri A , in the constellation Cancer. The solar system’s secondary star, 55 Cancri B, is a red dwarf star which is located about 159,321,732,615 km from the primary star.

Scientists say that while the primary star can be seen with the naked eye, it takes ideal conditions such as a clear and moonless night.

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An artist’s concept of exoplanet 55 Cancri e as it closely orbits its star 55 Cancri A (NASA/JPL-Caltech) (Click Image to Download)

Previous studies have found that the planet makes one complete orbit around its sun in about 18 hours and that since its daytime temperature can reach nearly 1,700° Celsius, 55 Cancri e is not at all hospitable to life.

A number of small, extra-solar planets are expected to be discovered in the next ten years as new observational space missions — including NASA’s Transiting Exoplanet Survey Satellite (TESS) , and the European Space Agency’s Planetary Transits and Oscillations of Stars (PLATO)  –are launched.

Both PLATO – set to go in 2014 and TESS, scheduled for a 2017 launch – will look for transiting Earth-like planets circling nearby bright stars.

Source : blogs.voanews.com

You can soon bury your DNA on Moon!


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A British space consultant will charge people 50 pounds or so to place a sample of their DNA in an archive to be buried on the Moon. Called Lunar Mission One, the archive is the brainchild of David Iron, who has worked on Skynet, the UK spy satellite network, and Galileo, the European Union’s global positioning system. He will offer people a chance to place a sample of their DNA, in the form of a strand of hair, in an archive to be buried on the Moon, alongside a digital history of as much of their lives as they want to record.

However, Iron needs at least 10 million people to do this if he is to generate the 500 million pounds the moon shot will need, ‘New Scientist’ reported.

Iron and his colleagues have launched a crowdfunding campaign on Kickstarter to raise the initial 600,000 pounds of seed funding needed to set up the company to commission designs for the spacecraft, which it is hoped will blast off in 2024. Iron is working with the Rutherford Appleton Laboratory in Harwell, UK.Lunar Mission One plans to land a robotic spacecraft on the Moon’s south pole. It will then drill at least 20 metres into the lunar crust, extracting core samples to be analysed on the craft. “No lunar or planetary mission of any kind has ever drilled to a significant depth below the surface. The deepest Apollo drill core was only 3 metres long,” said Ian Crawford at Birkbeck College, London, Lunar Mission One’s chief planetary scientist.

“The drill will enable the geothermal gradient, and thus lunar heatflow, to be measured for the first time,” Crawford said.

After about six months, capsules containing the DNA and digital data will be injected into the borehole, which will then be sealed.

Source : Deccan herald

Esa’s mission to Jupiter is GO! ‘Juice’ spacecraft will launch in 2022


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  • Jupiter and its moons could be best hope of finding signs of alien life
  • Jupiter icy moons explorer (Juice) will reach the Jovian system in 2030
  • It will explore volcanic Io, Europa and rock-ice Ganymede and Callisto
  • Juice will also take a look at Jupiter’s atmosphere and magnetosphere

Astronomers claim Jupiter and its moons could provide the best hope of finding signs of alien life in our solar system.

Now, in an effort to explorer its distant oceans, the Jupiter icy moons explorer (Juice) mission has been given the green light to launch in 2022.

The five-tonne satellite will reach Jupiter in 2030 where it will use its suite of instruments to explore the planet’s atmosphere, magnetosphere and tenuous set of rings.

Juice will also look at Jupiter’s diverse Galilean moons – volcanic Io, icy Europa and rock-ice Ganymede and Callisto – which make the Jovian system a miniature solar system in its own right.

The focus will largely be on Ganymede, though, and will the first time any icy moon has been orbited by a spacecraft.

Earlier this year, scientists said Ganymede might have ice and oceans stacked up in several layers similar to a club sandwich.

Previously, the moon was thought to harbour a thick ocean sandwiched between just two layers of ice, one on top and one on bottom, but now it seems it has multiple layers.

Scientists claims that places where water and rock interact are important for the development of life. For example, it is possible life began on Earth in bubbling vents on our sea floor.

Prior to the new study, Ganymede’s rocky sea bottom was thought to be coated with ice, not liquid – a problem for the emergence of life.

It will visit Callisto, the most heavily cratered object in the solar system, and will twice fly by Europa.

Juice is hoping to make the first measurements of the thickness of Europa’s icy crust and will identify candidate sites for future in situ exploration.

The Galileo mission found strong evidence that a subsurface ocean of salty water is in contact with a rocky seafloor.

Source : Daily mail

Astronomers Discover 7 New Galaxies Using Subaru Telescope


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Man’s quest to discover life and new galaxies in the outer space had been going on for ages now. We For long, scientists have been using advanced technologies to search for life and planets in our very own Akashganga, also known as Milky way. But now, the talk of the town is seven galaxies that Japanese scientists have discovered in the outer space.

The fact was revealed in the recent Astrophysical Journal, which cites that space scientists have found seven new galaxies (seemed to be appearing from nowhere), 700 million years after the Big Bang. The researchers believe that this would help them unleash deeper mysteries of the universe and its galaxies.

Wondering, who discovered it? Well, the galaxies have been discovered by a team of astronomers in Japan, led by graduate student Akira Konno and Dr Masami Ouchi, using the Subaru Telescope. The team was searching for low mass galaxies, also known as Lyman-alpha Emitters (LAEs), in the space.

Akira Konno cites, “At first we were very disappointed at this small number, but we realized that this indicates LAEs appeared suddenly about 13 billion years ago. This is an exciting discovery. We can see that the luminosities suddenly brightened during the 700 to 800 million years after the Big Bang. What would cause this?”

In order to investigate the phenomenon of cosmic reionisation, he and his team searched for early LAE galaxies at a distance of 13.1 billion light years.

Notably, galaxy clusters are the most massive objects in the universe that consist of hundreds to thousands of galaxies, pulled together by gravity.

Nearly 13.8 billion years ago, the universe was born in an event called the Big Bang. During the same period, first stars and galaxies were formed. Later, the ultraviolet light of these objects were ionised, which is also known as process called ‘cosmic reionisation’.

Source : Gizmodo

NASA gets green light for ‘space taxi’ project with Boeing


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Artistic impression of Boeing’s Space Taxi

Boeing is moving full speed ahead with ambitious plans to build and fly America’s and indeed the world’s first private spaceships destined to transport humans to orbit, after being awarded the lion’s share of NASA’s commercial crew contract barely two month ago.

Boeing’s slice of the contract is worth $4.2 billion, while SpaceX captured $2.6 billion of the project.

Source : bizjournals,SEN

Success in the search for quiet, distant quasars


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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