Astronomers: Alien planet’s atmosphere may explain solar system formation

The planet in question, called HR 8799c, is one of four gas giants known to circle a star 130 light-years from Earth.

By Max Sonnenberg, The Space Reporter
Friday, March 15, 2013

Astronomers: Alien planet’s atmosphere may explain solar system formation

Astronomers believe that an alien planet’s atmosphere may explain the mystery of solar system formation, according to a news release from the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto. Astronomers studied the atmosphere of a Jupiter-like planet well beyond our own Solar System.

According to Quinn Konopacky of the Dunlap Institute for Astronomy & Astrophysics, the team of astronomers used the Keck II telescope’s advanced instrumentation to examine the new alien world in “unprecedented detail.” Konopacky notes that the nature of the planetary system as well as ground-breaking observing and data-processing techniques also helped astronomers learn about the exoplanet’s atmosphere.

The team of astronomers studied the alien planet’s atmosphere using a high-resolution imaging spectrograph called OSIRIS. They discovered a cloudy atmosphere containing carbon monoxide and water vapor.

Co-author Travis Barman, a Lowell Observatory astronomer, says that astronomers can learn about the formation of the planetary system by comparing the amount of carbon to the amount of oxygen present in the alien world’s atmosphere.

The two leading models of solar system formation are called core accretion and gravitational instability. Studying a planet’s atmosphere helps astronomers identify whether a system formed under the core accretion model or the gravitational instability model.

According to the news release, the planet’s carbon to oxygen ratio suggests that the alien world formed according to the core accretion model, which is the model scientists think explains the formation of our own Solar System.

The planet in question, called HR 8799c, is one of four gas giants known to circle a star 130 light-years from Earth. Though HR 8799c and the other gas giants were found back in 2008 and 2010, this is the first time that astronomers have studied HR 8799c’s atmosphere in detail. According to astronomers, HR 8799c has a mass three to seven times that of Jupiter.

The core accretion model suggests that the star HR 8799 was originally surrounded by a large disk of gas and dust. As the gas cooled and ice formed, the disk was depleted of oxygen atoms. The ice and dust formed planetary cores which eventually attracted surrounding gas to form large atmospheres.

The core accretion model also suggests that these gas giants formed at great distances from HR 8799. Rocky planets, however, form closer in, making them ideal candidates for extraterrestrial life.

In fact, Konopacky says that she would not be surprised to discover Earth-like planets orbiting HR 8799.

The Keck II 10-meter telescope in Hawaii is one of the largest optical telescopes in the world. Astronomers contend that Keck’s adaptive optics and high spatial resolution, when combined with advanced data-processing techniques, help them study distant solar systems.

Co-author Christian Marois of the National Research Council of Canada says that the planets orbiting HR 8799 are easy to study because they are all “large, young, and very far from their parent star.”

The astronomers plant to continue studying the Jupiter-size planets to better their understanding of the planets’ atmospheres. “The more we learn about this distant planetary system, the more we learn about our own,” notes Konopacky.

The study’s findings were published Thursday in Science Express and will be published next Friday in the journal Science.


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