A team of researchers from the University of California has discovered that the exoplanet WASP-69 b is gradually losing its atmosphere. Its particles are gathering into a giant gas tail, looking like a comet tail.
WASP-69 b was discovered back in 2013. It is a gas giant orbiting an orange dwarf located 164 light-years from Earth. The exoplanet’s mass is 82 times that of Earth, and its orbit is less than 7 million kilometers from its parent star.
Because of this proximity, the atmosphere of WASP-69 b is heated to very high values. Its day side temperature exceeds 800 °C. Under the influence of powerful stellar radiation, hydrogen and oxygen atoms are gradually dislodged from the upper atmosphere of WASP-69 b. But observations have shown that this process is more complex than previously thought. Instead of flying evenly throughout the system, under the influence of the stellar wind, these particles form an enormous tail that stretches behind WASP-69 b. It makes the planet resemble a giant comet.
The researchers’ measurements have shown that the length of this tail exceeds 560 thousand kilometers, which is equivalent to 7.5 radii of WASP-69 b. For comparison, the average distance between the Earth and the Moon is 384,000 kilometers.
But it’s quite possible that the tail is even longer. The team had to finish the observations on the telescope before the tail signal disappeared. Therefore, this measurement is the lower limit of the true tail length at this time. It is important to keep in mind that since the tail is influenced by the stellar wind, changes in the activity of the star can change the size and shape of the tail over time.
Astronomers have also calculated how much gas WASP-69 b loses. They estimate this figure to be 200,000 tons per second. At first glance, this is a gigantic figure — but it’s relatively small on the scale of a gas giant. For every billion years, an exoplanet loses an amount of material equal to the mass of Earth. Since the system is 7 billion years old, it has lost about seven Earth masses — or 7.8% of its original mass. So it’s not in danger of disappearing anytime soon.
Earlier we told you about the exoplanet found by the James Webb Telescope, the density of which is comparable to cotton candy.
Provided by NASA
