Jupiter-like Exoplanet Reveals Hot Spot on Its Side

A team of astronomers has determined that a hot Jupiter-class exoplanet is featuring an impressively hot spot on its surface, but not where scientists expected to find based on the common laws of physics.

Studies of the planer Upsilon Andromedae b have shown that the gas giant orbits its parent star at such close range that the two are tidally locked.

This means that the objects always keeps the same face oriented at the stars, much like the Moon always has the same face oriented towards Earth. This is a tidally locked system as well.

But closer investigations of the hot Jupiter exoplanet have revealed that the space body features a structure that can best be described as a hot spot on one of its sides, which doesn't make sense.

If the planet and its parent stars are locked together as they move through space, than the highest temperatures on the exoplanet should be recorded on the face that it keeps oriented towards the Sun at all times.

But that doesn't seem to be the case with Upsilon Andromedae b, which features a hot spot that is located on one of its sides. Astronomers have no idea as to why this happens.

“We really didn't expect to find a hot spot with such a large offset. It's clear that we understand even less about the atmospheric energetics of hot Jupiters than we thought we did,” says Ian Crossfield.

The expert, who was the lead author of the new investigation, is based at the University of California in Los Angeles (UCLA), Space reports.

Even though the exoplanet is about three quarters the mass of Jupiter, it spins around its parent star in around 4.6 days, due to the proximity between the two.

Upsilon Andromedae b is located in the constellation Andromeda, at a distance of about 44 light-years from Earth. It was recently analyzed with the NASA infrared Spitzer Space Telescope.

“This is a very unexpected result. Spitzer is showing us that we are a long way from understanding these alien worlds,” says Spitzer project scientist Michael Werner.

The expert holds an appointment with the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, but he was not a part of the new research.

Using Spitzer, astronomers were able to determine that the exoplanet was not brightest when behind its parent star, as normal, but when it was located on the side of its star.

This hints at the fact that the hottest area on Upsilon Andromedae b is located on its side, and not on its Sun-facing side.

Details of the new study have accepted for publication, and will appear in an upcoming issue of the esteemed Astrophysical Journal.