Astronomers discover new planet in planetary system similar to our own
By ANIThursday, December 9, 2010
LONDON - Astronomers have announced the discovery of a fourth giant planet outside our solar system, strengthening the similarities between a distant planetary system and our own.
The astronomers say the planetary system resembles a supersized version of our solar system.
“Besides having four giant planets, both systems also contain two ‘debris belts’ composed of small rocky or icy objects, along with lots of tiny dust particles,” said Benjamin Zuckerman, a UCLA professor of physics and astronomy.
The newly discovered fourth planet (known as HR 8799e) orbits a bright star called HR 8799, which lies some 129 light years from Earth and is faintly visible to the naked eye.
Astronomers estimate that the combined mass of the four giant planets may be 20 times greater than the mass of all the planets in our solar system.
“This is the fourth imaged planet in this planetary system, and only a tiny percentage of known exoplanets (planets outside our solar system) have been imaged; none has been imaged in multiple-planet systems other than those of HR 8799,” Zuckerman said.
All four planets orbiting HR 8799 are similar in size, likely between five and seven times the mass of Jupiter. The newly discovered planet orbits HR 8799 more closely than the other three.
“The four massive planets pull on each other gravitationally,” said co-author Quinn Konopacky, a postdoctoral researcher at LLNL.
“We don’t yet know if the system will last for billions of years or fall apart in a few million more. As astronomers carefully follow the HR 8799 planets during the coming decades, the question of the stability of their orbits could become much clearer.”
How these planets originated is still a puzzle.
“Astronomers can now directly examine the atmospheric properties of four giant exoplanets that are all the same young age and that formed from the same building materials,” said Travis Barman, a Lowell Observatory exoplanet theorist.
To overcome the planet’s relative faintness and its proximity to its star, Macintosh is leading an effort to build an advanced exoplanet imager, called the Gemini Planet Imager, for the Gemini Observatory.
This new instrument will physically block the starlight and allow quick detection and detailed characterization of planets similar to HR 8799e.
The study has been published in Nature. (ANI)
