The cold spot contains very little even by intergalactic standards and it is a very large patch of very little. Statistically speaking it shouldn't be a surprise, there are a lot smaller regions that have similar properties, this one just happens to be the largest one known.

"Wait... so if I understand correctly, if a star emits in the ultra-violet, it MUST also emit in the visible spectrum. "

Yes

"But if a star emits in the infra-red, it can be invisible as far as the visible spectrum is concerned?"

Yes

"But it will not have nuclear fusion running... "

Yes, unless we detect it as a infrared source due to redshift (would have to be very far away) but that case one would be looking at a normal star.

"If a "star" doesn't have nuclear fusion, doesn't that mean it's not a star?"

Things aren't so simple. White dwarves don't have have atomic fusion reactions (save infalling matterial) and most of their light output is due to heat.

They don't actually look like anything unless mater falls into one. As matter falls in it heats up and then gives off light at ever shorter wavelengths as it gets hotter. If the there is enough matter falling in, then there will be a disk of matter around the black hole's equator and a pair of jets along the pole as some of that matter is ejected from the disc.

well thank you very much.. I'm going to mull it over. (of course I could also study a bit... I suppose ; )