Caltech Team Discovers 18 New Planets
PASADENA, Calif. (KTLA) -- There are 18 new planets in the universe -- and they're all orbiting around stars larger than the sun.

The discovery of confirmed planets was made by a team of Caltech astronomers and was published in the December issue of the astronomy journal, The Astrophysical Journal Supplement, the university announced Friday.

The astronomers worked out of the Keck Observatory in Hawaii with follow-up observations at facilities in Texas and Arizona. The find is especially significant because it's the first to be made from Earth.

"It's the largest single announcement of planets in orbit around stars more massive than the sun, aside from the discoveries made by the Kepler (orbital) mission," says John Johnson, assistant professor of astronomy at Caltech and leader of the project.

The team focused on "retired" A-type stars, which are one and a half times larger than the sun and just past the main stage of their life.

The 18 "Jupiter-like" were found in the gravitational pull of these large stars.

According to Johnson, the find increases the number of known planets by 50% and provides a new understanding of how planets, and our own solar system, might form.

But because these planets have such wide orbits, the findings take several years to become apparent. Johnson says he started the research as a graduate student at the university.

"I liken it to a garden—you plant the seeds and put a lot of work into it," he said. "Then, a decade in, your garden is big and flourishing. That's where I am right now. My garden is full of these big, bright, juicy tomatoes—these Jupiter-sized planets."