Astronomers at the Massachusetts Institute of Technology have announced the discovery of an exoplanet about 140 light-years away from Earth. It’s literally falling apart.
The discovery was made with the help of TESS. It detected changes in the brightness of the star BD+05 4868 A, located in the constellation Pegasus. Every 30.5 hours its brilliance decreases slightly, telling us that it has an invisible companion. It has been given the designation BD+05 4868 Ab. What is most intriguing is that the shape of the star’s light curve changes during each transit. This means ― something that passes in front of a star is not always the same shape and does not always block the same amount of light.
As a result, astronomers came to the legitimate conclusion that the exoplanet has a long tail. After analyzing all available data, they found that BD+05 4868 Ab is a small rocky exoplanet whose mass is comparable to Mercury’s, and whose orbit runs at a distance 20 times smaller than the distance between the Sun and Mercury. Apparently, the exoplanet’s surface is covered by an ocean of magma that boils out into space, forming a tail whose length reaches 9 million kilometers. As a result, BD+05 4868 Ab is actually vaporized.
Astronomers estimate that during each revolution BD+05 4868 Ab ejects an amount of material equivalent to Mount Everest. At this rate, given its small mass, the researchers predict that the planet could completely disintegrate in about 1-2 million years.
It is only the fourth decaying world found by researchers outside our solar system. Meanwhile, BD+05 4868 Ab has the longest tail and deepest transits of all. Which means its vaporization will be the most catastrophic, and it will disappear much faster than other exoplanets. This, and the exoplanet’s great proximity to its star, make it an ideal target for observations with the James Webb Space Telescope. It will be able to determine the mineral composition of its tail by identifying which wavelengths of infrared light it absorbs.
We previously reported on how James Webb exonerated a star accused of absorbing its exoplanet.
According to Phys.org
