Astronomers have caught a red giant star in the act of devouring one of its planets. It could be a preview of what will happen to Earth five billion years from now.
Astronomers Discover Giant Star "Digesting" Its Own Planet
First Evidence Discovered of Planet's Destruction by Its Star
The first evidence of a planet's destruction by its aging star has been discovered by an international team of astronomers. The evidence indicates that the missing planet was devoured as the star began expanding into a "red giant" - the stellar equivalent of advanced age.
"A similar fate may await the inner planets in our solar system, when the Sun becomes a red giant and expands all the way out to Earth's orbit some five-billion years from now" - Alex Wolszczan, an Evan Pugh Professor of Astronomy and Astrophysics at Penn State, University, who is one of the members of the research team. Wolszczan also is the discoverer of the first planet ever found outside our solar system.
Title: BD+48 740 - Li overabundant giant star with a planet. A case of recent engulfment? Authors: M. Adamów, A. Niedzielski, E. Villaver, G. Nowak, A. Wolszczan
We report the discovery of a unique object, BD+48 740, a lithium overabundant giant with A(Li)=2.33 ±0.04 (where A(Li) = log(n_Li/n_H) + 12), that exhibits radial velocity (RV) variations consistent with a 1.6 M_J companion in a highly eccentric, e = 0.67 ±0.17 and extended, a=1.89 AU (P=771 d), orbit. The high eccentricity of the planet is uncommon among planetary systems orbiting evolved stars and so is the high lithium abundance in a giant star. The ingestion by the star of a putative second planet in the system originally in a closer orbit, could possibly allow for a single explanation to these two exceptional facts. If the planet candidate is confirmed by future RV observations, it might represent the first example of the remnant of a multiple planetary system possibly affected by stellar evolution.