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




EXO WORLDS
Study On Extrasolar Planet Orbits Suggests That Solar System Structure Is The Norm
by Staff Writers
Geava, Italy (SPX) Apr 12, 2012


The EXOEarths team (Centro de Astrofisica da Universidade do Porto - CAUP), in collaboration with Geneva University, did a joint analysis of data from the HARPS spectrograph and the Kepler satellite. This analysis revealed that the orbits of other planetary systems are aligned, like in a disk, just like in our own solar system. More images, movies and detailed captions.

Recently, the HARPS spectrograph and the Kepler satellite made a census of the planetary population around stars like our own, revealing a bounty of planetary systems. A follow-up study lead by members of the EXOEarths team (Centro de Astrofisica da Universidade do Porto - CAUP), in collaboration with Geneva University, did a joint analysis of the data which showed that the planetary orbits in a system are strongly aligned, like in a disk, just as we have in our own solar system.

The two most effective methods for detecting extrasolar planets are the radial-velocity method and the transit method. The radial-velocity method detects planets through the reflex motion induced by the planet on the star's velocity on the radial direction (hence the name). This velocity variation is detected through the Doppler effect, the same that leads to a pitch change in the sound of an traveling ambulance.

On the other hand, a planetary transit is akin to a mini-eclipse. As a planet travels around the star, its orbit can locate it in front of the star, and the light we collect from the star is reduced because the planet blocks part of it (even though we cannot image the planet).

There is a significant difference when these two methods are applied to planetary system. A planet can be detected in radial velocity even when the orbit's plane direction is tilted relative to the line of sight, and the same is true for a system of planets.

However, for a planet to transit, the plane of its orbit has to be almost perfectly aligned with our line-of-sight, and the same is true for a system of two (or more planets) to transit. This means that if several planets in a system transit they form necessarily a very small angle between them.

We simulated planetary systems with frequencies as reported by HARPS survey (that detects basically all the systems, independently of their inclination angle), and attributed to them different relative inclinations. The frequency of transiting systems was calculated and compared with the values reported by Kepler.

We showed that a match can be obtained for double-transiting systems only if they are very strongly aligned with a common plane (the system's plane). This alignment has to be close to 1 degree, and only reaches 5 degrees on very extreme cases (extreme on the sense of the assumption on how a planetary mass translates to a radius).

These results show consistently that the planets' orbits are predominantly aligned, reinforcing the idea that planets form on a disk and suggesting for the first time that violent encounters between planets are not frequent. This provides a very important clue about the formation and evolution of exoplanets, a domain in which several open questions remain. Even though the solar system's organization is more often the exception than the rule, this study shows that the high degree of alignment of our system might well be the norm.

Pedro Figueira (CAUP), the article's first author stated: "These results show us that the way our solar system formed must be common. Its structure is the same as the other planetary systems we studied, with all planets orbiting roughly in the same plane."

The article "Comparing HARPS and Kepler surveys: The alignment of multiple-planet systems" (Figueira et al.) was accepted for publication in Astronomy and Astrophysics. It's available here. The team is composed by P. Figueira (Centro de Astrofisica da Universidade do Porto), M. Marmier (Observatory of Geneva), G. Boue (Centro de Astrofisica da Universidade do Porto), C. Lovis (Observatory of Geneva), N. C. Santos (Centro de Astrofisica e Faculdade de Ciencias, Universidade do Porto), M. Montalto (Centro de Astrofisica da Universidade do Porto), S. Udry (Observatory of Geneva), F. Pepe (Observatory of Geneva), M. Mayor (Observatory of Geneva).

.


Related Links
Centro de Astrofisica da Universidade do Porto
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








EXO WORLDS
When Stellar Metallicity Sparks Planet Formation
Moffett Field CA (SPX) Apr 11, 2012
In new research, scientists have attempted to determine the precise conditions necessary for planets to form in a star system. Jarrett Johnson and Hui Li of Los Alamos National Laboratory assert that observations increasingly suggest that planet formation takes place in star systems with higher metallicities. Astronomers use the term "metallicity" in reference to elements heavier than hydr ... read more


EXO WORLDS
Russia postpones Luna-Glob moon mission

Russia Plans to Launch Lunar Rovers to Moon after 2020

Russia to explore moon

Earth's Other Moons

EXO WORLDS
Mars Express - Pit chains on the Tharsis volcanic bulge

Post Solstice Rover Takes The Opportunity For A Wiggle

Russia and Europe give boost to Mars robotic mission

Mars missions race, India takes lead

EXO WORLDS
Commentary: Innovate or evaporate

United Launch Alliance Announces New Human Launch Services Organization

Private Lunar mission and the future of space tourism

Inventors limber up for Geneva showcase

EXO WORLDS
China's Lunar Docking

Shenzhou-9 may take female astronaut to space

China to launch 100 satellites during 2011-15

Three for Tiangong

EXO WORLDS
Learn to dock ATV the astronaut way

Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES)

Busy first days for ATV Edoardo Amaldi

Space Savings for ISS Science Samples

EXO WORLDS
Dragon Expected to Set Historic Course

NASA Awards Launch Contract For Goes-R And Goes-S Missions

Spy satellite-carrying rocket blasts off

Orbital Receives Order for Minotaur I Space Launch Vehicle From USAF

EXO WORLDS
When Stellar Metallicity Sparks Planet Formation

Study On Extrasolar Planet Orbits Suggests That Solar System Structure Is The Norm

NASA Extends Kepler, Spitzer, Planck Missions

NASA's Kepler Mission Awarded Mission Extension

EXO WORLDS
US sues Apple, publishers yield on e-book pricing

Instagram fans moan over slap in the Facebook

Sony straps on Internet-linked wristwatch

An efficient method for solving sound propagation in range-dependent ocean waveguides found




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