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Gamma Cephei IV

September 5, 2012

BENEDICT: The process of science is messy...

Fritz Benedict is a Texas astronomer who’s leading a team that’s studying Gamma Cephei, a system of two stars and one known planet. The goal is to find out whether all three objects orbit in the same plane — an observation that’s important to understanding the formation of all planets.

The team has used Hubble Space Telescope to precisely plot the position of one of the stars as it’s pulled by its orbiting planet. That should reveal the mass of the planet — a key bit of intel in plotting the system’s layout. But while the Hubble observations were good, the overall results have been frustrating.

BENEDICT: You say, ‘Whoa, that’s a nice result. I like that result. The orbit fits the data very nicely.’ Then you double check things. And the double check is to go to our friends who find out if systems are dynamically stable or not. And they come back instantly — almost within a day. ‘Bad news — this is not a stable system.’ That’s a huge red flag that we have not got the right answer.

The problem is with the orbit of the two stars — something that’s crucial to measuring the position of the target star. But the stars take so long to orbit each other that the researchers have had to rely on plots made over many decades. But those plots give results that don’t make sense.

So the astronomers will need continued observations of Gamma Cephei to better plot the orbits of the two stars. Only then will they know how the system is laid out — a bit of stellar geometry that’ll help explain the formation of all planetary systems.


Script by Damond Benningfield, Copyright 2012

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