A reddish speck photographed near a dim and distant star last year is indeed a planet, about five time the mass of Jupiter, an international team of astronomers reported. They say the results bolster their claim, put forward last fall, that this image was the first of a planet orbiting a star outside the solar system. The planet, about 230 light-years from Earth in the constellation Hydra, orbits a kind of failed star known as a brown dwarf at a distance of at least five billion miles, twice as far as icy Neptune is from our own Sun.