If the signal was produced by intelligent aliens with a beacon transmitting radio waves in all directions, the energy it would need to produce 10^20 watts
If instead the beacon was targeted at Earth, then the power needed drops to 10^13 watts
Before astronomers jump to any conclusion, they’re attempting to detect the signal again. Last night, the SETI Institute used the Allen Telescope Array in northern California to track the star. They saw nothing, but will observe again tonight.
Centauri Dreams Paul Gilster broke the story
Paul Gilster had seen a presentation on the matter from Italian astronomer Claudio Maccone.
"Permanent monitoring of this target is needed," said the presentation.
Nick Suntzeff, a Texas A&M University astronomer told the online magazine Ars Technica that the 11 gigahertz signal was observed in part of the radio spectrum used by the military.
"If this were a real astronomical source, it would be rather strange," Suntzeff was quoted as saying. Nick believes the signal was a closer regular military source.
SOURCES - New Scientist, Centauri Dreams