* Astronomy

Light echo of a high-energy flash from a black hole first observed in detail
A light echo occurs when interstellar gas is heated by radiation and reacts by emission of light. An international team led by Stefanie Komossa from the Max Planck Institute for extraterrestrial Physics in Garching, Germany, has observed the light echo of an enormous X-ray flare, which was almost certainly produced when a single star was disrupted by a supermassive black hole. For the first time, the light echo of such a rare and highly dramatic event could be observed in great detail. The light echo not only revealed the stellar disruption process, but it also provides a powerful new method for mapping galactic nuclei (Astrophysical Journal Letters, Mai 2008).

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The same team of astrophysicists that cracked the computer code simulating two black holes crashing and merging together has now, for the first time, caused a three-black-hole collision.
Manuela Campanelli, Carlos Lousto and Yosef Zlochowerscientists in Rochester Institute of Technologys Centre for Computational Relativity and Gravitationsimulated triplet black holes to test their breakthrough method that, in 2005, merged two of these large mass objects on a supercomputer following Einsteins theory of general relativity.
The new simulation of multiple black holes evolving, orbiting and eventually colliding confirmed a robust computer code free of limitations. The May issue of Physical Review D will publish the teams latest findings in the article Close Encounters of Three Black Holes, revealing the distinct gravitational signature three black holes might produce. The story will run under the Rapid Communications section.

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Title: The fuzzball proposal for black holes
Authors: Kostas Skenderis, Marika Taylor

The fuzzball proposal states that associated with a black hole of entropy S there are exp S horizon-free non-singular solutions that asymptotically look like the black hole but generically differ from the black hole up to the horizon scale. These solutions, the fuzzballs, are considered to be the black hole microstates while the original black hole represents the average description of the system. The purpose of this report is to review current evidence for the fuzzball proposal, emphasizing the use of AdS/CFT methods in developing and testing the proposal. In particular, we discuss the status of the proposal for 2 and 3 charge black holes in the D1-D5 system, presenting new derivations and streamlining the discussion of their properties. Results to date support the fuzzball proposal but further progress is likely to require going beyond the supergravity approximation and sharpening the definition of a "stringy fuzzball". We outline how the fuzzball proposal could resolve longstanding issues in black hole physics, such as Hawking radiation and information loss. Our emphasis throughout is on connecting different developments and identifying open problems and directions for future research.

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