Two new papers in the Astronomical Journal show that in some multiplanet systems, giant planets tend to kick their smaller neighbors out of orbit and wreak havoc on their climates.
In one of the two papers, University of California, Riverside astrophysicist Stephen Kane detailed how the pull of massive planets in the HD 141399 system is likely to toss their Earth-like neighbors out of the habitable zone.
HD 141399 is an early K dwarf star located 121 light-years away in the constellation of Boötes.
The star harbors four giant planets with masses in the range between 0.45 and 1.36 Jupiter masses.
Unlike most other known planetary systems, these four planets are farther from their parent star.
“The HD 141399 system of four giant planets is exceptionally rare among known exoplanetary architectures,” Professor Kane said.
“According to the NASA Exoplanet Archive, HD 141399 is one of only two known planetary systems with at least four planets that are all more massive than Saturn.”
“The other system is HR 8799, with four wide-separation planets that were detected via direct imaging.”
“Thus, the HD 141399 system is an incredible opportunity to study the formation, dynamics, and evolution of an unusual planetary architecture.”
Taking data about the system’s planets into account, Professor Kane ran multiple computer simulations to understand the effect of these four giants.
He wanted specifically to look at the habitable zone in this star system and see if an Earth could remain in a stable orbit there.
“The answer is yes, but it’s very unlikely. There are only a select few areas where the giants’ gravitational pull would not knock a rocky planet out of its orbit and send it flying right out of the zone,” Professor Kane said.
While the first paper shows giant planets outside the habitable zone destroying the chances for life, the second paper, by Professor Kane and his colleague, University of California, Riverside’s Dr. Tara Fetherolf,…
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