We usually think that planets have some degree of permanence, but for worlds that are in the immediate vicinity of a star, that can be fleeting. One particular kind of exoplanet astronomers want to know about is the so-called "hot neptunes," overheated giants that are incredibly rare.
Now, researchers using the Hubble Space Telescope have determined exactly what they believe a planet that is about to be considered "hot Neptune", and that it is so close to its star that the planet actually does evaporated in front of our eyes.
The exoplanet, called GJ 3470b, is near what researchers call the "Hot Neptune Desert" around the host star. Scientists believe that such planets are lacking because over time they are completely destroyed because of their close relationship with the stars they orbit, and GJ 3470b may be the next one to go on.
One of the planets of GJ 3470b is GJ 436b. Astronomers believe they lose their atmosphere when their star pulls them away. Scientists believe that 436b will survive the ordeal without being completely destroyed. However, 3470b is at a much harder point. 3470b is deprived of mass 1
"I think this is the first case where this is so dramatic in terms of planetary evolution," Vincent Bourrier University of Geneva and co-author of the paper said in a statement. "It's one of the most extreme examples of a planet that suffers a massive mass loss throughout its lifetime. This significant mass loss has significant implications for its development and affects our understanding of the origin and fate of the population of exoplanets that are close to their stars.
How close is it when it comes too close to planets and their stars? The planet closest to our own sun, the hot-glowing Mercury, has been trying for a long time, but 3470b is much closer to its star. In fact, both 436b and 3470b are only a tenth of the distance of their star away from Mercury from the Sun.