Personally, I didn't discover any.
So far we haven't been able to get anything to another star, a galaxy is a million times farther away.
The largest star discovered so far is the UY Scuti red supergiant. It is approximately 1,708 solar radii, where one solar radii equals the radius of the Sun in our solar system.
So far, Jupiter is the largest planet in our solar system.
That depends on how you define "celestial body". Arguably, the largest "celestial body" thus far discovered (or ever likely to be discovered) is the universe itself. However, let's assume you mean a compact body, i.e. one which is more or less continuous (and thus excludes things like galaxies, globular clusters, and nebulae). The largest star known is VY Canis Majoris, which is roughly the size of the orbit of Saturn. The largest body in the Solar system is, of course, the Sun. Jupiter is second, at about 0.1% the volume of the Sun.
Thiomargarita namibiensis is the largest microorganisms found so far. It can get up to 0. 75mm and was discovered in 1997, on the seafloor.
The largest mountain so far discovered is Olympus Mons on Mars, at about 76,000 feet tall.
No. The largest carnivorous dinosaur discovered so far is the Spinosaurus.
Apparently, Argentinosaurus is the largest dinosaur discovered so far. There is always a chance that an even larger dinosaur may be discovered - so updating the current accepted dinosaur facts.
yes
The Sun is, so far as we can determine, the ONLY star in the solar system. If it's not the only one, it's certainly the largest. (Look up "Nemesis" for some thoughts on why it might not be the only one.)
there is no moon which is larger than Ganymede in our Solar System. Ganymede is the largest natural satellite (moon) in our Solar System so far to be discovered.
The biggest star is VY canis majoris! It is believed that it is 2000 times bigger than the sun!!!!! And trust me its true