(ORDO NEWS) — WASP-12b is one of the most interesting exoplanets we know of. This ultra-black planet, orbiting a yellow dwarf star a bit larger than the Sun, is 1,410 light-years away.
This gas giant is almost identical in mass and size to Jupiter, but is extremely close to its star, with a period of just over a day around it. The exoplanet is so close to its star that a stream of material is constantly pumped out of its atmosphere.
Careful observations have shown that WASP-12b is in a markedly decreasing orbit. And, according to new research, this orbit is shrinking faster than previously thought. Astronomers have found that the planet will die in the bowels of its star in 2.9 million years.
According to modern models of planetary formation, “hot Jupiters” should not exist. A gas giant cannot form so close to a star because gravity, radiation, and strong stellar winds must keep the gas from building up. However, in spite of everything, they exist, and astronomers have already identified about a hundred such planets.
At the same time, “hot Jupiters” are well studied and can tell us a lot about the tidal interactions between the planet and the star. WASP-12b is one of the hottest Jupiter’s closest to its star. And this is a great example for studying tidal interactions.
The planet was discovered in 2008 and astronomers have compiled a relatively long-term dataset about it, and WASP-12b’s short orbit means there are a huge number of transits available for study.
WASP-12b is an optically very dark object: it absorbs 94 percent of all incident light, making it blacker than asphalt. Astronomers believe that the reason lies in the temperature of the planet, which reaches 2600 ° C. On the daytime side of the planet, hydrogen molecules split into atomic hydrogen, making its atmosphere more like a low-mass star. But due to the high temperature, it glows in the infrared range.
By observing the exoplanet’s transits and the periods when it hid behind its star, a team of researchers led by Jake Turner from Cornell University discovered fluctuations in the duration of these events and came to the conclusion about the rapid orbital decay of WASP-12b.
The exoplanet is steadily approaching its star, which means that it has less than 3 million years left to live, which is considered almost an instant by cosmic standards. However, the researchers note that the planet would have been awaiting death without orbital decay. In about 10 million years, WASP-12b would have perished from an atmospheric rupture.
The authors of the work believe that further observation of WASP-12b may provide us with a lot of new data. And while this is the only exoplanet for which we have reliable evidence of orbital decay, there are many more “hot Jupiters” that may exhibit similar behavior.
The authors of the study conducted observations of WASP-12b from December 24, 2019 to January 20, 2020 using the Transiting Exoplanet Survey Satellite (TESS) space telescope, designed to search for exoplanets by the transit method.
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