Learn the formation of the planet through

Astronomers used unexpected objects to study the development of planets - dead stars.

Observations by NASA's Spitzer Space Telescope reveal six dead 'white stars' with the rest of the small planets disintegrating. This may seem confusing, but the disintegrated small planets teach astronomers about planetary construction materials around other stars.

So far, the research results show that materials that form our Earth and solar system may be common in the universe.If materials form rocky planets are common, rocky planets may also be common.

Michael Jura of the University of California, Los Angelse, who presented the results at the meeting of the American Astronomical Society in Long Beach, Calif., Said: 'If you group small planets and rocky planets, they I have the same kind of dust in the star systems. This shows that stars also have small planets like us - and so there can also be rocky planets'. Jura is the main author of the paper published in Astronomical magazine

Small planets and planets form dusty materials around young stars. Dust gather together, form blocks and eventually create planets. Small planets are extra fragments.When a star like the sun nears the end of its life it bursts into a giant red mass that destroys the nearest planets, and pushes small planets and planets outside. This process continues, it blows away the outer layers and shrinks into a white star.

Sometimes, a small planet moves too close to a white star and is destroyed - the gravity of the white star breaks down the small planet into pieces. The same thing happened with Shoemaker Levy 9 Comet when Jupiter's gravity broke it, before the comet finally crashed into the planet in 1994.

Siptzer observed debris of a small planet around white stars with machines around the infrared spectrum, a device that could break light into a rainbow of wavelengths, showing traces of chemicals. Previously, Spitzer analyzed small planetary dust around two white stars, new observations that increased the total number of white planets analyzed to 8.

An illustration of a dead star, or 'white star' surrounded by fragments and parts of a small planet that disintegrates. (Photo: NASA / JPL-Caltech)

Jura said: 'Currently, we have a larger specimen of these white stars, so these types of events are not too rare anymore.'

Of the eight observed systems, Spitzer found that dust contains glass silicate minerals similar to olivine and can be found on Earth. Jura commented: 'This is the clue that stone materials around these stars have evolved similarly to ours.'

Spitzer data also shows that there are no carbon in the observed rocks - again like small planets and rocky planets in our solar system.
A small planet is thought to have crumbled several million years ago in one of the eight white star systems mentioned above. The largest of them ever had a diameter of 200 km (124 miles), slightly larger than Los Angeles.

Jura said the real benefit of observing these white star systems is still ahead. When a small "eat dust" around a dead star, it breaks into very small pieces.Planetary dust around ordinary stars, on the contrary formed from larger particles.

By continuing to use spectroscopy to analyze light often from these dust layers, astronomers can observe in great detail - including information about the chemical elements present. This will reveal more about how other star systems classify and process planetary materials.

Jura said: 'It's like white stars separate dust for us'.

Other authors include Ben Zuckerman of the University of California, Los Angeles, and Jay Farihi of Leicester University, United Kingdom.

The research was funded by NASA and the National Science Foundation. NASA's Jet Laboratory in Pasadena, Calif., Manages the Spitzer Space Telescope for NASA's Science Directorate in Washington. Scientific activities are conducted at the Spitzer science center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information about Spizer can be accessed at http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer.