1) This one is actively ingesting material (active galaxy) so there are emissions from the accretion disk. Our galaxy is quiet, so there isn't the same emission from the black hole.
2) The one in our galaxy is 1600x closer and roughly that much smaller, so they're approximately the same angular size.
3) They have tracked the orbit of a star that orbits our galaxy's central black hole through an orbit, and it goes ~2% (iirc) of the speed of light at closest approach, but it's nowhere near the event horizon. There are other things that have been tracked near A*, but nothing at the event horizon like this one.
Comments
1) This one is actively ingesting material (active galaxy) so there are emissions from the accretion disk. Our galaxy is quiet, so there isn't the same emission from the black hole.
2) The one in our galaxy is 1600x closer and roughly that much smaller, so they're approximately the same angular size.
3) They have tracked the orbit of a star that orbits our galaxy's central black hole through an orbit, and it goes ~2% (iirc) of the speed of light at closest approach, but it's nowhere near the event horizon. There are other things that have been tracked near A*, but nothing at the event horizon like this one.