Showing posts with label dwarf planets. Show all posts
Showing posts with label dwarf planets. Show all posts

Saturday, August 27, 2011

Diamond planet discovered - Ka-ching, ladies?

Now would you mind having some nice planet-sized diamond sparkling on your ring finger? Space science is all about the bling.

Article:

Surprise! Alien Planet Made of Diamond Discovered
by Nola Taylor Redd, SPACE.com Contributor - 25 August 2011


This illustration shows the alien planet around pulsar PSR J1719-1438, where ultra-high pressures caused carbon to crystallize in the remnant of a dead star. The planet is made of diamond and orbits a dense pulsing star with a radius smaller than that of our sun. CREDIT: Swinburne Astronomy Productions

A newly discovered alien planet that formed from a dead star is a real diamond in the rough.

The super-high pressure of the planet, which orbits a rapidly pulsing neutron star, has likely caused the carbon within it to crystallize into an actual diamond, a new study suggests.

The composition of the planet, which is about five times the size of Earth, is not its only outstanding feature. [Illustration of the diamond alien planet]
The planet's parent star is a special kind of flashing star known as a millisecond pulsar, a rapidly rotating neutron star formed from a supernova. The entire system, which is only the second of its kind ever discovered, is located about 4,000 light-years from Earth in the constellation of Serpens (The Snake).

A gem of a find
Seventy percent of millisecond pulsars found have a companion, which provides additional energy to ramp up the pulsars' rapid rotation. Generally, this companion is a dying star called a white dwarf; more than 180 millisecond pulsars have been found with white dwarfs over the years.

Theonly planet known to be orbiting in such a system was detected in 1992 — until now."The pulsar was found in December 2009," lead scientist Matthew Bailes of Swinburne University of Technology in Melbourne, Australia, told SPACE.com via email."We've been on the trail of the companion ever since." [The Strangest Alien Planets

Video: Massive diamond plaent orbits neutron star, astronomers find

From the ashes of a supernova
Known as PSR J1719-1438, this particular pulsar completes more than 10,000 rotations in a minute. Tiny and compact, it's only about 12 miles (20 kilometers) across, but it has a mass that is 1.4 times that of our sun.

PSR J1719-1438 transformed from an average star to a radio pulsar when a dying star in a binary system exploded. The compact core of the star formed with a very high rotation speed from the ashes of the supernova.
When the second star in the system reached the end of its life, it expanded as a red giant and finally morphed into a white dwarf. The pulsar began to suck mass off its companion, causing the pulsarto spin faster and faster until it attained its breakneck speed.

From dying star to diamond planet
What happened next depends on the system. Most white dwarfs continue to orbit the new millisecond pulsar, but some are consumed by it.

"The fate depends upon the mass of the white dwarf and how far it is from the pulsar," Bailes said.
If it is both close and massive, the two spiral together. Astronomers assume this is what happened to the 30 percent of millisecond pulsars found without a companion. [Top 10 Star Mysteries]

In the case of the diamond planet, astronomers think that the core of the white dwarf failed to merge completely with its companion.
"When they got very close, the star lost a lot of its matter and moved out to its safe distance of about a solar radius," Bailes said.

Now tiny, having lost more than 99.9 percent of its original mass and no longer engaged in the fusion reactions that drive a star, the dead core is classified as a planet.
Ironically, the star-turned-planet is larger than its sun. With a diameter of about 37,300 miles (60,000 km), it's five times the size of Earth, but 3,000 times larger than the millisecond pulsar it orbits.

The planet itself orbits the pulsar in a little more than two hours. The entire system would fit within the diameter of our sun.
The research was published online in the Aug. 25 edition of the journal Science.

Source: Space.com

Tuesday, July 26, 2011

Howdy, P4! You are Pluto's moon number 4!

The Hubble Space Telescope just revealed that Pluto obviously has a fourth moon, that remained undiscovered until now. It was provisorily called "P4" by astronomers (Wiki article). This is just another sign how little we know about our own solar system so far - and how many great discoveries may remain for us out there!

Pluto Moon P4 in its orbit:

Two labeled images of the Pluto system, released on July 20, 2011, taken by the Hubble Space Telescope's Wide Field Camera 3 ultraviolet visible instrument with newly discovered fourth moon P4 circled. The image on the left was taken on June 28, 2011. The image of the right was taken on July 3, 2011. CREDIT: NASA, ESA, and M. Showalter (SETI institute) - Full Size.

Article:

Pluto Has Another Moon, Hubble Photos Reveal

Date: 20 July 2011 Time: 09:35 AM ET - SPACE.com Staff

A tiny new moon has been discovered around Pluto, the fourth and smallest one yet found orbiting the dwarf planet, photos from the Hubble Space Telescope reveal.
The moon, which has been temporarily named P4, was spotted in a Hubble survey searching for rings around Pluto.

The tiny satellite is estimated to be between 8 and 21 miles (13 to 34 kilometers) wide. For comparison, Pluto's largest moon Charon is 648 miles (1,043 km) across. The dwarf planet's other moons, Nix and Hydra, range between 20 to 70 miles across (32 to 113 km). [Photo of Pluto's new moon]
"I find it remarkable that Hubble's cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km)," Mark Showalter of the SETI Institute in Mountain View, Calif. said in a statement. Showalter led this observational survey with Hubble.


Illustration of the Pluto Satellite System orbits with newly discovered moon P4 highlighted. CREDIT: NASA, ESA, and A. Feild (STScI)

New moon around Pluto
Pluto's new moon is located between the orbits of Nix and Hydra, which Hubble also discovered in 2005. Charon was discovered in 1978 at the U.S. Naval Observatory and was first resolved using Hubble in 1990 as a separate body from Pluto.

The finding is a result of ongoing work to support NASA's New Horizons mission, which is scheduled to fly through the Pluto system in 2015. The mission is designed to provide new insights about worlds at the edge of our solar system.
Hubble's photos of Pluto's surface and the discovery of its satellites have been invaluable for planning for New Horizons' close encounter.
"This is a fantastic discovery," said New Horizons' principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colo. "Now that we know there's another moon in the Pluto system, we can plan close-up observations of it during our flyby."

Pluto's moon system
The dwarf planet's entire moon system is believed to have formed by a collision between Pluto and another planet-sized body early in the history of the solar system. The galactic smashup flung material that combined into the family of satellites observed around Pluto.

Our own moon is thought to have been created by a similar collision between Earth and a Mars-sized body 4.4 billion years ago. Lunar rocks that were returned to Earth from the Apollo missions led to this theory, and scientists think material blasted off Pluto's moons by micrometeoroid impacts may form rings around the dwarf planet.
So far, Hubble's photographs have yet to show any such rings, but the detection of P4 shows that big discoveries can sometimes be unexpected.

"This surprising observation is a powerful reminder of Hubble's ability as a general purpose astronomical observatory to make astounding, unintended discoveries," Jon Morse, director of the astrophysics division at NASA Headquarters in Washington, D.C., said in a statement.
P4 was first seen in a photo taken with Hubble's Wide Field Camera 3 on June 28. It was confirmed in subsequent Hubble pictures taken on July 3 and July 18. The moon was not seen in earlier Hubble images because the exposure times were shorter.

There is a chance that P4 appeared as a very faint smudge in images from 2006, but was overlooked because it appeared obscured, scientists said.
Pluto was discovered in 1930, but its planethood was thrown into question when the International Astronomical Union came up with a new definition of "planet" in 2006. That year, Pluto was demoted to the status of "dwarf planet," a newly created category to describe many other objects in the Kiper Belt, the ring of icy bodies beyond Neptune.

Source: space.com