Q&A: Black Holes

Q:
What do the team at Chandra think of the alternative argument for "Black Hole" type phenomena such as "Gravistars" as described in Scientific American?

A:
Alternative theories for objects as bizarre as black holes are usually worth considering. One challenge for this alternative is to explain Chandra observations that indicate the existence of an event horizon. See, for example, http://chandra.harvard.edu/photo/2001/blackholes/index.html