Washington: Gemini Observatory`s Planet-Finding Campaign has found that distant gas-giant planets are rare and prefer to cling close to their parent stars.
The impact on theories of planetary formation could be significant.
"It seems that gas-giant exoplanets are like clinging offspring," Michael Liu of the University of Hawaii`s Institute for Astronomy and leader of the Gemini Planet-Finding Campaign, said.
"Most tend to shun orbital zones far from their parents. In our search, we could have found gas giants beyond orbital distances corresponding to Uranus and Neptune in our own Solar System, but we didn`t find any," he said.
The Campaign was conducted at the Gemini South telescope in Chile, with funding support for the team from the National Science Foundation and NASA.
The Campaign`s results, Liu says, will help scientists better understand how gas-giant planets form, as the orbital distances of planets are a key signature that astronomers use to test exoplanet formation theories.
The findings are published in The Astrophysical Journal.