While watching The Empire Strikes Back on BluRay, I noticed a ship flying with the rebel fleet near the end of the movie that I never noticed. As far as I know, this ship is in none of the books. It looks small--Millennium Falcon sized maybe-- and has a side-by-side, twin "B-wing-ish" cockpit configuration in the front and a long trailing fuselage in the rear. Has anyone else noticed this ship and is there anything to know about it? Does it have a name, what is its purpose, etc.?