It is a phenomenon documented only a few times before.
A physicist at the University of Notre has captured crisp, clear images of a “hot Jupiter.” This newly found planet inhabits a three-star system — a phenomenon documented only a few times before.
Justin R. Crepp, Freimann Assistant Professor of Physics, was part of the team that discovered the planet. It is called a “hot Jupiter” because it is a gas giant that orbits extremely close to one of the stars in its solar system.
The researchers used KELT, the Kilodegree Extremely Little Telescope, to detect the presence of the planet, now named KELT-4Ab, which is located about 685 light-years from Earth. KELT monitors bright stars in large sections of the sky, searching for planets orbiting extremely closely.
Crepp was then asked to use the Keck Telescope to investigate and capture photos. In doing so, he ended up finding two additional stars.
“I found that there was a dot nearby, which we believed to be a star, making this a binary system,” Crepp said in a University of Notre Dame news release. “And then upon further review, I found that it was two dots. We wouldn't have realized that without these photos.”
Diagram displays KELT-4A, the star that hot jupiter orbits, and KELT-4B,C, the two other stars. Photo credit: Justin R. Crepp/University of Notre Dame
KELT-4Ab is about one and a half times the size of Jupiter, and it orbits the system’s primary star every three days. But the other two stars orbit each other once every 30 years while simultaneously orbiting the main star — and the planet — once every 4,000 years.
“We are trying to learn how planets get to their final resting places in orbits around stars,” Crepp said. “This discovery has implications for our understanding of planet formation and evolution.”
Until the mid-1990s, scientists believed that gas giants like Jupiter could only be found far from the stars they orbit, just like Jupiter in our solar system. However, when the first hot-Jupiter was discovered in 1995, those assumptions went right out the window. Since then, Crepp and other astronomers have been looking for these hot-Jupiters to determine how they got there.
“We still think they formed far from their star, but then somehow migrated close to their stars. We also don't know how they stop migrating,” Crepp explained. “It is possible that companion stars drive the dynamics of planets such as to move the planets closer to the star.”
Now that Crepp has found another gas giant so close to its star and in a triple star system, he can start comparing it to what they are seeing in other solar systems. Crepp concluded, “When you first find these, you're hunting and gathering. Once you have enough objects, we can start looking for patterns.”
The study was published in The Astronomical Journal.
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