The latter was taken around the entire cosmos and saw its entities like palm of his hand. So we learn from detailed accounts of authentic ahadith. We are far too amazed to gauge the true nature of his self, let alone his knowledge of the universe. There are fully developed galaxies in the universe like our own Milky Way and Andromeda, our nearest neighbour. There are gigantic bodies of primeval smoke still, such as the Small Megallanic Cloud and Large Megallanic Cloud.
Stars come in a variety of colours, mass, volumes, contents and nature.
There are red giants that are lot more voluminous. Our sun, tiny in size, belongs to white dwarf category. It is a medium grade star by weight. The universe abounds in stars that are more massive - by a time and a half to tens, hundreds and thousands. The near toppers start condensing by their own internal gravity and eventually get so dense that atomic structure breaks down resulting in a plasma of only neutrons.