Weird warm spot on an exoplanet

As more exoplanets are found on virtually a weekly basis, it is becoming apparent how diverse they are, sometimes with peculiar characteristics not seen before. Such is the case with the large “hot Jupiter” planet upsilon Andromedae b, which orbits very close to its star and so is searingly hot on the side facing the star (it keeps the same side toward the star, as the moon does as it orbits the Earth). Well, not quite. For some reason, the “hot spot” with the highest temperature is about 80 degrees away, almost on the other side of the planet.

Credit: NASA/JPL/Caltech

The observations were made using the Spitzer Space Telescope, and astronomers don’t have an explanation yet, but theories include supersonic winds and star-planet magnetic interactions.