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 innerplanets 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," said Alex Wolszczan, an Evan Pugh Professor of Astronomyand Astrophysics at Penn State, University, who is one of the members of the research team. Wolszczan also is the discoverer ofthe first planet ever found outside our solar system.
The astronomers also discovered amassive planet in a surprisingly elliptical orbit around the same red-giant star, named BD+48 740, which is older than the Sun with a radius about eleven times bigger. Wolszczan and the team's other members, Monika Adamow, Grzegorz Nowak, and Andrzej Niedzielski of Nicolaus Copernicus University in Torun, Poland; and Eva Villaver of the Universidad Autonoma de Madrid in Spain, detected evidence of the missing planet's destruction while they were using the Hobby-Eberly Telescope to study the aging star and to search for planets around it.The evidence includes the star's peculiar chemical composition, plus the highly unusual elliptical orbit of its surviving planet.

Could we ever go back in time?

Axions are hypothetical particles with a very low mass. According toEinstein, mass is directly related toenergy, and therefore very little energy is required to produce axions. "The existence of axions is not proven, but it is considered to be quite likely," says Daniel Grumiller. Together with Gabriela Mocanu he calculated at the Vienna University of Technology (Institute for Theoretical Physics), how axions could be detected. Astronomically Large Particles In quantum physics, every particle is described as a wave. The wavelength corresponds to the particle's energy. Heavy particles have small wavelengths, but the low-energy axions can have wavelengths of many kilometers. The results of Grumiller and Mocanu, based on works by Asmina Arvanitaki and Sergei Dubovsky (USA/Russia), show that axions can circle a black hole, similar to electrons circling the nucleus of an atom. Instead of the electromagnetic force, which ties the electrons and the nucleus together, it is the gravitational force which acts between the axions and the black hole. The Boson-Cloud However, there is a very importantdifference between electrons in an atom and axions around a black hole: Electrons are fermions -- which means that two of them can never be in the same state. Axions on the other hand are bosons, many of them can occupy the same quantum state at the same time. They can create a "boson-cloud" surrounding the black hole. This cloud continuously sucks energy from the black hole and thenumber of axions in the cloud increases.