2 Answers

The largest planet ever discovered is also one of the strangest and theoretically should not even exist, scientists say.
Dubbed TrES-4, the planet is about 1.7 times the size of Jupiter and belongs to a small subclass of "puffy" planets that have extremely low densities. The finding will be detailed in an upcoming issue of Astrophysical Journal.
"Its mean density is only about 0.2 grams per cubic centimeter, or about the density of balsa wood," said study leader Georgi Mandushev of the Lowell Observatory in Arizona. "And because of the planet's relatively weak pull on its upper atmosphere, some of the atmosphere probably escapes in a comet-like tail."
The planet's large mass-to-density ratio makes it an anomaly among known exoplanets, and its existence cannot be explained by current models.
A planet anomaly
"TrES-4 is way bigger than it's supposed to be," Mandushev told Space.com. "For its mass, it should be much smaller. It basically should be about the size of Jupiter and instead it's almost twice as big."
"TrES-4 appears to be something of a theoretical problem," said study team member Edward Dunham, also of the Lowell Observatory. "Problems are good, though, since we learn new things by solving them."
The planet is located about 1,400 light years away from Earth and zips around its parent star in only three and a half days. An international team of astronomers discovered it using a network of automated telescopes called the Trans-Atlantic Exoplanet Survey. TrES-4 was detected as it passed in front of, or "transited," its parent star, called GSC 02620-00648. The transit technique is the only planet-finding method that allows scientists to calculate the size of a planet.

TrES-4 "is the largest planet found so far for which we actually know the size," Mandushev said in a telephone interview. "There could be larger planets, but we have no way of measuring their sizes because they don't transit."

13 years ago. Rating: 0
Comment this answer Add new comment

The planet, dubbed HAT-P-1, is located some 450 light-years from Earth in the constellation Lacerta.

13 years ago. Rating: 0
Comment this answer Add new comment