Can you get a thing like that within the sol's closest space? I mean, if there was one somewhere between us and say alpha centauri or barnard's star, is it possible that you cannot feel it's gravity force?
Wheheyyy... it's not _my_ novel! Found it on yahoo by some dude from England:
http://uk.search.yahoo.com/search?fr=fp-tab-web-t-1&ei=ISO-8859-1&p=interstellar+ark+to+alpha+centauri&meta=vc%3D
This gigantic thing here called the Centauri Princess, can it be built in the next few hundred years?
http://www.astroscience.org/abdul-ahad/firstarktoalphacentauri.htm
That would be the greatest engineering achievement in all human history...
<<<three planets have been detected
the inner one is too hot
the outer one is too cold
but the middle one would be roughly same average temp as earth>>>
If that middle one is a _rocky_ planet then there is every hope for life. So they should steer the SETI dishes in this direction now...
If by _habitable_ you imply will be able to support life, then I think okay - if your calcs are right. If you imply has life, then I think difficult if not impossible, because sirius A is too young a system, and Sirius B will have gone through red giant phase relatively recently, disrupting all...