noun.
The application of photography to the delineation or record of solar spots, the moon's disk, the planets, and the constellations, and to other astronomical ends.
the GNU version of the Collaborative International Dictionary of English
noun.
The application of photography to the delineation of the sun, moon, and stars.
noun.
A specialized kind of photography, comprised of concepts and techniques that pertain to the production of photographicimages of astronomical objects.
Word Usage
"We also went to see the open air astrophotography exhibition in St Andrews Square."