Astronomers discover planet made of diamonds

It is certainly what you could call a gem of a discovery.

Astronomers believe they have found an entire planet made of diamonds.

Scientists at the University of Manchester think they have unearthed a once-massive star in the Milky Way that has been transformed into a small planet made of the precious rock.

The diamond planet - the shrunken core of a once-huge
star - is a chunk of crystallised carbon measuring
40,000 miles across, five times the diameter of Earth.

The international research team first detected an unusual star, called a pulsar, and followed up their discovery with research using a telescope based in an observatory in Cheshire.

 
The findings led the scientists to discover the gravitational pull of a small companion planet orbiting the pulsar.

Pulsars are small spinning stars more than ten miles in diameter – the size of a small city – that emit a beam of radio waves.

The team, also made up of scientists from Australia, Germany, Italy and the United States, thinks that the ‘diamond planet’ is all that remains of the original star, most of whose matter was siphoned off towards the pulsar.

The companion planet is small, at less than 40,000 miles wide – about five times the diameter of Earth.

 
But it is so close to the pulsar that if it were any bigger it would be ripped apart by the gravitational force of the star, which rotates more than 10,000 times per minute and has a mass of about 1.4 times that of the sun.

Research team member Dr Michael Keith said: 'This remnant is likely to be largely carbon and oxygen, because a star made of lighter elements like hydrogen and helium would be too big to fit the measured orbiting times.'

The density means that this material is certain to be crystalline, that is, a large part of the star may be similar to a diamond.

The pulsar, dubbed PSR J1719-1438, and its planet are part of the Milky Way's plane of stars and lie 4,000 light-years away in the constellation of Serpens - the Snake.

The modulations in the radio pulses told astronomers a number of things about the planet.

It orbits the pulsar in just two hours and ten minutes, and the distance between the two objects is about 373,000 miles - a little less than the radius of our sun.

Despite its small size, the planet has slightly more mass than Jupiter.
 
About 70 per cent of millisecond pulsars have companions of some kind. 
 
Astronomers think it is the companion that, in its star form, transforms an old, dead pulsar into a millisecond pulsar by transferring matter and spinning it up to a very high speed.

The result is a fast-spinning millisecond pulsar with a shrunken companion - most often a so-called white dwarf.

source: dailymail

Super-massive black hole caught shredding a star to pieces for the first time

A stunning cosmic jet from a super-massive black hole which shredded then swallowed a star has been observed by astronomers for the first time.

The extremely rare phenomenon caused by stellar debris being consumed by the hole has never been observed before.

Known as 'relativistic jets', they can reach hundreds of thousands of light years in length.

This illustration shows plasma shooting out of the
black hole after it devours a star. Such an event took
place four billion light years from Earth

Swift's Ultraviolet/Optical (white, purple) and X-ray
telescopes (yellow and red) showing the bursts

Most galaxies have super-massive black holes - regions of space that suck in everything nearby with their strong gravitation pull - at their core, with masses of millions or even billions of suns.

Scientists were first alerted to the phenomenon in March after Nasa's Swift telescope detected several bursts of X-rays from a quiet patch of sky.

Teams from both Pennsylvania State University and the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said the bursts could be the remnants of a star pulled apart when it came too close to a black hole located 3.9billion light years away.

Dr David Burrows, from Pennsylvania State University which controls Swift, said chemical analysis of the bright flash's ultraviolet light show it comes from material being sucked into a black hole the size of a million suns.

Writing in Nature, they concluded that the Swift satellite just happened to be in the path of the jet of star remains that were shot out at 99.5 per cent the speed of light.

Dr Burrows said: 'Incredibly, this source is still producing X-rays and may remain bright enough for the Swift satellite to observe into next year. It behaves unlike anything we've seen before.'

The swallowing of a star by a black hole only happens once every one hundred million years in a galaxy. The black hole is now believed to be even more powerful because of the additional mass from the swallowed star.

The absorption of large mass such as stars or even other black holes is what gives black holes growth and spawn the existence of super-massive black holes.Super-massive black holes could contain up to billions of solar masses. By comparison, the sun is just one solar mass and the Earth is 1/332,950th of a solar mass.


source: dailymail

Discovered: Stars as Cool as the Human Body

Scientists using data from NASA's Wide-field Infrared Survey Explorer (WISE) have discovered six "Y dwarfs"-- star-like bodies with temperatures as cool as the human body.

This artist's conception illustrates what a "Y dwarf"
 might look like.

Astronomers hunted these dark orbs for more than a decade without success. When viewed with a visible-light telescope, they are nearly impossible to see. WISE's infrared vision allowed the telescope to finally spot the faint glow of a half dozen Y dwarfs relatively close to our sun, within a distance of about 40 light-years.

"WISE scanned the entire sky for these and other objects, and was able to spot their feeble light with its highly sensitive infrared vision," says Jon Morse, Astrophysics Division director at NASA Headquarters in Washington.

The Y's are the coldest members of the brown dwarf family. Brown dwarfs are sometimes referred to as "failed" stars. They are too low in mass to fuse atoms at their cores and thus don't burn with the fires that keep stars like our sun shining steadily for billions of years. Instead, these objects cool and fade with time, until what little light they do emit is at infrared wavelengths. The atmospheres of brown dwarfs are similar to those of gas giant planets like Jupiter, but they are easier to observe because they are alone in space, away from the blinding light of a parent star.

So far, WISE data have revealed 100 new brown dwarfs. Of these, six are classified as cool Y's. One of the Y dwarfs, called WISE 1828+2650, is the record holder for the coldest brown dwarf with an estimated atmospheric temperature cooler than room temperature, or less than 80 degrees Fahrenheit (25 degrees Celsius).

The coldest brown dwarf known so far, is denoted by a
green dot in very center  of this infrared image.
The chilly star-like body isn't even as warm as a human
  body, at less than about 80 degrees Fahrenheit.

"The brown dwarfs we were turning up before this discovery were more like the temperature of your oven," says Davy Kirkpatrick, a WISE science team member at the Infrared Processing and Analysis Center at Caltech. "With the discovery of Y dwarfs, we've moved out of the kitchen and into the cooler parts of the house."

The Y dwarfs are in our sun's neighborhood, from approximately nine to 40 light-years away. The Y dwarf approximately nine light-years away, WISE 1541-2250, may become the seventh closest star system, bumping Ross 154 back to eighth. By comparison, the star closest to our solar system, Proxima Centauri, is about four light-years away.

"Finding brown dwarfs near our sun is like discovering there's a hidden house on your block that you didn't know about," says Michael Cushing, a WISE team member at JPL. "It's thrilling to me to know we've got neighbors out there yet to be discovered. With WISE, we may even find a brown dwarf closer to us than our closest known star."

Once the WISE team identified brown dwarf candidates, they turned to NASA's Spitzer Space Telescope to narrow their list. To definitively confirm them, the WISE team used some of the most powerful telescopes and spectrometers on Earth to split apart the objects' light and look for telltale molecular signatures of water, methane and possibly ammonia. For the very coldest of the new Y dwarfs, the team used NASA's Hubble Space Telescope. The Y dwarfs were identified based on a change in these spectral features compared to other brown dwarfs, indicating they have a lower atmospheric temperature.


source: NASA

Space hotel: a room with intergalactic view

Tiring of the annual two-week break in a Med hot spot? Fed up with overcrowded resorts with no room to move?
Then how about a real get-away-from-it-all holiday with plenty of space – in space?

Russia yesterday announced plans for a hotel in orbit 217 miles up which would house seven guests in four cabins and have huge windows for views of the Earth turning below.

 

Futuristic: Orbital Technologies has revealed plans for a
space hotel,which could be open by 2016

Just getting there will be an adventure in itself – it will take two days aboard a Soyuz rocket – and it won’t exactly be a budget holiday: A five-day stay will cost you £100,000, on top of £500,000 for your journey.

The hotel, or the Commercial Space Station to give it its proper name, is due to open by 2016 and, according to those behind it, will be ‘far more comfortable’ than the International Space Station used by astronauts and cosmonauts.

In the weightlessness of space, visitors can choose to have beds that are either vertical or horizontal, while showers will be sealed affairs to stop water going where it shouldn’t (those aboard the International Space Station must make do with sponge baths until they return home).

Tourists, who will be accompanied by experienced crew, will dine on food prepared on Earth and sent up on the rocket, to be reheated in microwave ovens.

The plan is to do away with the freeze-dried tubes of nourishment given to astronauts and replace them with delicacies such as braised veal cheeks with wild mushrooms, white bean puree, potato soup and plum compote.

Space age: The rooms will also act as an emergency
bothole for astronauts at the manned space station

Iced tea, mineral water and fruit juices will be available, but alcohol will be strictly prohibited. Toilets will use flowing air instead of water to move waste through the system.
Waste water will be recycled, while the air will be filtered to remove odour and bacteria and then returned to the cabin.
Sergei Kostenko, chief executive of Orbital Technologies which will construct the hotel, said: ‘Our planned module inside will not remind you of the International Space Station. A hotel should be comfortable inside, and it will be possible to look at the Earth through large portholes.

‘The hotel will be aimed at wealthy individuals and people working for private companies who want to do research in space.’

Tourists might also find themselves playing host to unexpected guests – there is a plan for the hotel to be used as an emergency bolthole for astronauts aboard the International Space Station if there is a crisis, rather than bringing them all the way back to Earth.

source: dailymail