Johanssen, Psaltis and astronomer Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics looked closely at the best-studied black hole binary,
A0620-00, which has been observed for about a decade.
"The strongest celestial X-ray source ever ob served (except for the sun) is a remarkable temporary object recently discovered in the constellation Monoceros and known as
A0620-00."
Charles calls the findings the most definitive case yet for a black hole, surpassing previous evidence that other X-ray-emitting binary stars in the Milky Way -- Cygnus X-1 and
A0620-00 -- harbor black holes.
The X-ray transient A0620-00 in Monoceros, also known as V616 Monocerotis, is the prototypical SXT.
Remillard (MIT) obtained such data for A0620-00; coauthor Charles, Jorge Casares (Oxford University), and Tim Naylor (Keele University) have done it for another transient called V404 Cygni (S&T: November 1989, page 460).
"It's a rare event." The last comparable X-ray outburst occurred in 1975 from a source designated
A0620-00.
In late March, at a meeting of the Royal Astronomical Society in Leicester, Shahbaz described the team's application of this technique to the well-known SXT
A0620-00 in Monoceros, a leading black-hole candidate.
First, they noticed a striking resemblance between it and
A0620-00, another X-ray nova and strong black-hole candidate.