A Star Pulsing Mysteriously To Its Orbiting Planet Observed For The First Time

Astronomers at MIT have observed for the first time a star known as HAT-P-2 pulsing as a reaction to its orbiting planet, which is a gas giant planet that is about eight times the mass of Jupiter. The astronomers used the NASA's Spitzer Space Telescope in observing the HAT-P-2 for more than 350 hours.

Scientists observe first planet-induced stellar pulsations https://t.co/iHucgsSkTH pic.twitter.com/RgwFuTiqBH

— Brian Perry (@stellarflares) February 14, 2017

The gas giant planet is referred to as HAT-P-2b follows its star in an intense eccentric orbit. It flies very close to and around HAT-P-2, then plunging far out before circling back around. Meanwhile, as observed by the astronomers, the star appears to be vibrating at exact harmonics or multiples of the planet's orbital frequency. This is the rate at which the planet encircles its star.

The responses surprised and puzzled the astronomers. Julien de Wit, a postdoc in MIT's Department of Earth, Atmospheric and Planetary Sciences, said that they thought that planet cannot really excite their stars, but they found that this one does. She further said that there is a physical link between the two. But at this stage, they cannot explain it. She added that these are mysterious pulsations induced by the star's companion.

The team observed that the planet is an ideal system as it has an eccentric orbit. The planet oscillates between temperature extremes, turning cold as it moves far away from its star, then rapidly heating as it swings extremely close, according to Daily Galaxy.

Meanwhile, de Wit said that the star dumps an enormous amount of energy onto the planet's atmosphere and their original goal was to see how the planet's atmosphere redistributes this energy. The team also gauged the star's brightness to identify the amount of energy, in the form of heat, transferred to the planet. They also noticed that each time the planet passed behind the star, they saw tiny spikes, which are kinds of oscillations in the star's light, with a period of about 90 minutes, which happened to be the exact multiples of the planet's orbital frequency, according to Phys.org.