Letter: So how big is this Jupiter-sized black hole then?

From Richard Price, Chipping Sodbury, Gloucestershire, UK

You report that there may be an intermediate-mass black hole the size of Jupiter in our galaxy (19 January, p 14). Wouldn't one of these have significantly greater mass than the planet?

The editor writes:

• The diameter of the event horizon of the suggested black hole would be roughly Jupiter's diameter. The researchers say it would be about 30,000 times the mass of our sun.