Fifth-graders making styrofoam solar system models may have the right idea. Researchers at Lehigh University have discovered a new planet orbiting a star 320 light years from Earth that has the density of styrofoam. This “puffy planet” outside our solar system may hold opportunities for testing atmospheres that will be useful when assessing future planets for signs of life.
“It is highly inflated, so that while it’s only a fifth as massive as Jupiter, it is nearly 40 percent larger, making it about as dense as styrofoam, with an extraordinarily large atmosphere,” said Joshua Pepper, astronomer and assistant professor of physics at Lehigh University, who led the study in collaboration with researchers from Vanderbilt University and Ohio State University, along with researchers at universities and observatories and amateur astronomers around the world.
The research, “KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V+8 Subgiant HD 93396,” is published online in The Astronomical Journal.
The planet’s host star is extremely bright, allowing precise measurement of the planet’s atmosphere properties and making it “an excellent testbed for measuring the atmospheres of other planets,” Pepper said. Such observations help astronomers develop tools to see the types of gases in atmospheres, which will be necessary in the next 10 years when they apply similar techniques to Earthlike exoplanets with next-generation telescopes now under construction.