Some giant planets in other systems most likely to be alone

May 07, 2012
An artist's impression of a hot Jupiter planet. Image: NASA

In the search for Earth-like planets, it is helpful to look for clues and patterns that can help scientist narrow down the types of systems where potentially habitable planets are likely to be discovered. New research from a team including Carnegie's Alan Boss narrows down the search for Earth-like planets near Jupiter-like planets. Their work indicates that the early post-formation movements of hot-Jupiter planets probably disrupt the formation of Earth-like planets.

Their work is published the week of May 7 by .

The team, led by Jason Steffen of the Fermilab Center for , used data from NASA's to look at so-called "hot Jupiter" planets—those roughly Jupiter-sized planets with orbital periods of about three days. If a Jupiter-like planet has been discovered by a slight dimming of brightness in the star it orbits as it passes between the star and Earth, it is then possible—within certain parameters—to determine whether the hot-Jupiter has any companion planets.

Of the 63 candidate hot Jupiter systems identified by Kepler, the research team did not find any evidence for nearby companion planets. There are several possible explanations. One is that there are no companion planets for any of these hot Jupiters. Another is that the companions are too small in either size or mass to be detected using these methods. Lastly it is possible that there are companion planets, but that the configuration of their orbits makes them undetectable using these methods.

However, when expanding the search to include systems with either Neptune-like planets (known as "hot Neptunes"), or "warm Jupiters" (Jupiter-sized planets with slightly larger orbits than hot Jupiters), the team found some potential companions. Of the 222 hot Neptunes, there were two with possible companions, and of the 31 warm Jupiters, there were three with possible companions.

"The implications of these findings are that systems with Earth-like planets formed differently than systems with hot Jupiters," Boss said. "Since we believe that hot Jupiters formed farther out, and then migrated inward toward their stars, the inward migration disrupted the formation of Earth-like planets. If our sun had a hot , we would not be here."

Explore further: Astronomers find 'cousin' planets around twin stars

More information: Kepler constraints on planets near hot Jupiters, Published online before print May 7, 2012, doi: 10.1073/pnas.1120970109

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kevinrtrs
1 / 5 (7) May 08, 2012
Since we believe that hot Jupiters formed farther out, and then migrated inward toward their stars, the inward migration disrupted the formation of Earth-like planets.


Has this inward migration ever been observed and recorded?

Well, since we are only now getting to infer the existence of planets, the answer is a resounding NO.

So one has to question this belief. Just what is it that gives rise to this strange belief? Why would the mass that is "forming" the planet not start migrating inwards long before the planet is formed? Why wait until it actually exists in planetary form?
If a planet started migrating inwards, what is there to stop its movement once it got going?
I'm sure there are multiple mathematical models that show just how such migration can start and then stop, but one has to ask what assumptions are used and what basis do they have in reality since no such planetary migration has ever been observed.
kevinrtrs
1 / 5 (6) May 08, 2012
The existence of Hot Jupiters quite clearly blows the nebular theory of planetary formation out of the, well, sky. That theory, based on observations in our own solar system, predicts that such gaseous planets should exist far out from the host star. Yet here there are now multiple actual observations that show that those planets can exist in orbits that are mind-numbingly closer than Mercury to the sun. Exactly where they shouldn't be since the gases would supposedly have been blown away long before the planet could form all by itself.
So, do the researchers abandon the theory? No, new ad-hoc assumptions are made [and poorly justified] to bring the actual observations in line with the theory. Hence the "migration from further away" scenarios.
No matter the possibility of such migration happening in the mathematical models, there is zero current physical observation to substantiate it.
Shinichi D_
4.2 / 5 (5) May 08, 2012
Kevin, if I deny the obvious, can I too get to heaven?
antialias_physorg
not rated yet May 08, 2012
Finding that Hot Jupiters are solitary is interesting, but I wouldn't rule out the possibilities of life in such systems. Our own gas giants seem to be surrounded by a large number of moons - some of which seem promising as candidates for lifebearing (or at least water bearing) ecosystems (Titan, Europa, IO, .. ).
Unless there is a reason that Hot Jupiters have no moons it might be well worth having a closer look.

Yet here there are now multiple actual observations that show that those planets can exist in orbits that are mind-numbingly closer than Mercury to the sun.

Are you aware that stuff happens in the universe? You always start from a very simplistic/static model - so the first steps in your logic are already deeply flawed.

Look at the sky occasionally instead of into the bible. 5 minutes looking up will show you that the 'model' you have in your head is false.

Reality trumps literature. Every time.
Anorion
5 / 5 (3) May 08, 2012
Kevin, if I deny the obvious, can I too get to heaven?

no shin, so sorry, no one that have more than 3 neurons communicating with each other isn't accepted in heavens.
Mastoras
not rated yet May 08, 2012
Since we believe that hot Jupiters formed farther out, and then migrated inward toward their stars, the inward migration disrupted the formation of Earth-like planets.


Has this inward migration ever been observed and recorded?


I think this might have to do with one of Kepler's laws, connecting the mass, the distance from the sun and the period. I think.
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