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

The world that's darker than black

An artist's conception of how TrES-2b, the darkest planet
ever found, might look up close.

Astronomers say they've uncovered the darkest world ever, a planet blacker than coal that absorbs 99% of the light its star sends its way.

TrES-2b is a Jupiter-sized gas giant orbiting a star 750 light years from Earth in the direction of the constellation Draco. Astronomers found out the dark truth about TrES-2b using data from NASA's Kepler spacecraft, a satellite telescope to survey our Milky Way galaxy in search of Earth-like planets. TrES-2b won't fall into that category, however.

"TrES-2b is considerably less reflective than black acrylic paint, so it's truly an alien world," astronomer David kipping of the Harvard-Smithsonian Center for Astrophysics said in a press release. He is the lead author of a research paper n the dark planet submitted to the Monthly Notices of the Royal Astronomical Society.

Kipping and co-author David Spiegel of Princetion University say TrES-2b is a scalding world, with a temperature of about 1,800 degrees Fahrenheit. Its atmosphere probably contains vaporized sodium and potassium, or gaseous titanium oxide, all substances that absorb light but wouldn't alone account for the planet's darkness.

"It's not clear what is responsible for making this planet so extraordinarily dark," Spiegel said in a press release. "However, it's not completely pitch black. it's so hot that it emits a faint red glow, much like a burning ember or the coils on an electric stove."

TrES-2b revealed itself when as its orbit took it between Kepler and its star, changing the amount of light coming from the star ever so slightly.

"By combining the impressive precision from Kepler with observation of over 50 orbits, we detected the smallest-ever change in brightness from an exoplanet: just 6 parts per million," Kipping said in the press release. "In other words, Kepler was able to directly detect visible light coming from the planet itself."

source: CNN