Subscribe free to our newsletters via your
. 24/7 Space News .




EXO WORLDS
What a scorcher: 'Hot Jupiter' puzzle explained
by Staff Writers
Paris (AFP) May 11, 2011


Scientists on Wednesday said they could explain why heat-seared giant planets in other solar systems can mysteriously orbit their star the "wrong" way.

These space oddities belong to a class of planets known as hot Jupiters -- gassy giants that are the size of our own Jupiter but encircle their sun at sometimes scorchingly close distances.

What has bedevilled astronomers is the discovery that in some star systems, the host star spins one way while a hot Jupiter can orbit in the opposite direction.

This throws down a challenge to the yardstick of celestial mechanics, which is our solar system.

In our neighbourhood, all the planets trot obediently around the Sun in the same direction as its own spin. (The solar "day" -- the amount of time it takes for the Sun to complete one revolution at its equator -- is 26 days.)

"We had thought our solar system was typical in the Universe, but from day one, everything has looked weird in the extrasolar planetary systems. That makes us the oddball really," said Frederic Rasio, an astrophysicist at Northwestern University in Illinois.

In a study published by the science journal Nature, Rasio's team devised a model that, they believe, explains this contra-rotation conundrum.

The researchers start with the theoretical basis of a star that is similar in size to the Sun.

It has a system comprising two large planets that lie relatively close to each other and, initially, are located at a long range from the star. Each orbit the star in the "right" direction.

The idea for the model is that a combination of forces -- a gravitational coupling between the two planets as they near each other, and powerful tides on the innermost planet -- causes this cosy planetary system to break up.

Over a very long time, the inner planet starts to shift into an eccentric needle-shaped orbit, which gradually shrinks.

The planet is hauled in close to the star, creating the hot Jupiter, and in the process its orbit can flip.

But this is something that happens only in about a quarter of hot Jupiter systems that have been observed so far, says the paper.

Until now, one of the theories for explaining the flip was that it occurred in binary systems, where there are two stars, one of which exerted a gravitational tug that caused the planet to reverse course.

More than 500 extrasolar planets have been recorded since the first was detected in 1995.

One of the pioneers in this discipline, Swiss astronomer Didier Queloz, said that as techniques for planet-spotting improved, awareness was growing of the broad range of solar systems compared with our own, neat setup.

"Right now, the notion that solar systems are like ours is completely falling apart," Queloz, who did not take part in the new study, said in an interview with AFP.

"We are just one type of of solar system among an enormous diversity of planetary orbits and possibilities."

.


Related Links
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EXO WORLDS
An Earth as Dense as Lead
Moffett Field CA (SPX) May 02, 2011
A planet that we thought we knew turns out to be rather different than first suspected. A revised view comes from new data released by an international team of astronomers, who made their observations of the planet "55 Cancri e" based on calculations by Harvard graduate student Rebekah Dawson (Harvard-Smithsonian Center for Astrophysics). Dawson worked with Daniel Fabrycky (now at the Univ ... read more


EXO WORLDS
Space Adventures proposes modified Soyuz TMA for Lunar tourists

BRP To Contribute To Canadian Moon And Mars Exploration Programs

Naveen Jain Co-Founder And Chairman Of Moon Express

Project Morpheus To Begin Testing At NASA's Johnson Space Center

EXO WORLDS
Mars Express Sees Deep Fractures on Mars

Opportunity Images Small Craters

Exploring Rio Tinto Eurobotically

NASA Orbiter Reveals Big Changes in Mars' Atmosphere

EXO WORLDS
AFIT education paves way to space

Soyuz launch from Europe space base set for October

NASA, Space Community Remember 'Freedom 7'

NASA Selects 'Whipple' Mission for Technology Development

EXO WORLDS
Top Chinese scientists honored with naming of minor planets

China sees smooth preparation for launch of unmanned module

China to attempt first space rendezvous

Countdown begins for Chineses space station program

EXO WORLDS
ISS orbit to be readjusted for Soyuz TMA-20 return

Soyuz is in the launch zone at Europe's Spaceport

Progress Docks To ISS

Russia ferries supplies to space

EXO WORLDS
ST-2's installation on SYLDA marks the start of final payload integration for Ariane 5's next mission

Arianespace to launch ABS-2 in 2013

GSAT-8 put through its paces

Ariane Ariane 5 enjoys second successful launch for 2011

EXO WORLDS
What a scorcher: 'Hot Jupiter' puzzle explained

An Earth as Dense as Lead

Astronomers unveil portrait of 'super-exotic super-Earth'

Tuning Into ExoPlanet Radio

EXO WORLDS
Google notebooks challenge Microsoft

Broadband Lidar Instrument Successfully Tested on NASA's DC-8

Russia says fire put out near radioactive facility

Northrop Grumman Scalable SIRU Guides MESSENGER Spacecraft to Orbit Mercury




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement