The phrase "astronomical objects" refers to things that can be found in outer space, such as stars, planets, galaxies, and other celestial bodies. Full definition
He included it as object number 51 in his now - famous catalog of astronomical objects that, in a small telescope, might be mistaken for a comet. (public.nrao.edu)
It can observe large astronomical objects in their entirety in one go, and for each pixel measure the intensity of the light as a function of its colour, or wavelength. (sciencedaily.com)
More than a third of them can not be linked to any known astronomical object. (discovermagazine.com)