Geminga is the closest pulsar to the Earth at about 120 light years. It's in Gemini but I'm not sure where that would put it on the map of The Imperium. There's probably more neighboring pulsars too.
Yeah, I actually wrote a half-paragraph about Geminga in my earlier post (see above), but decided to eliminate it for time-constraint reasons.
Geminga has actually been bumped out to about 550 light years away, the last time I checked. Under the wonky Traveller 2D layout system I think I estimated it to be somewhere near the rimward edge of Charted Space, making it just within range for the Solomani to set up some kind of VERY isolated observation post, if they so desired.
And if the Imperium gets to play with that neutron star in the general direction of Antares, then I'd say it's a safe bet that the Solomani are all over Geminga like a dirty shirt.
But, y'know, it's Traveller mapping ... so your results may vary.
There are some other nearby neutron stars too I think.
But quasars are way out there, forget about running across them in the TU. Same for black holes. And it's just as well
I think the nearest
known black hole is at least several thousand light years away; but there may be one closer up in the general neighborhood that just hasn't been discovered yet. I'm no stellar physicists (although I play one on Science Fiction RPG message boards), but I suspect they're pretty hard to spot in the first place.
And you are absolutely correct that quasars are completely out of the question. Not only are they generally at the edge of the observable universe, but they also exist billions of years in the past. For all we know, someone 14 billion light years away from
us is looking in our direction and seeing a big honking quasar right where we should be.