Gamma Microscopii

A yellow giant star belonging to the faint group known as Microscopium, the Microscope, that runs southward of Capricornus and westward of Piscis Austrinus, the Southern Fish. Before the boundaries of the constellations were formally established, Flamsteed saw this star (and a handful of others now also in Microscopium) as belonging to Piscis Austrinus, and thus in his catalogue Gamma Microscopii is listed as '1 Piscis Austrini'. For this reason Flamsteed numbers within the modern constellation of Piscis Austrinus start with 5 Piscis Austrini, with the preceding four - including this one - having been lost to Microscopium.

Though it is designated 'Gamma', this is the brightest of Microscopium's stars, though with a visual magnitude of just +4.66, it is scarcely prominent, and requires clear skies to be visible at all. In fact both the Gamma and Alpha stars of Microscopium are variable in brightness, and at times they can come within just 0.04 magnitudes of one another.

Though Gamma Microscopii is now barely visible to the naked eye, this has not always been the case. Though it now lies about 250 light years out into space, about four million years ago it passed within just a handful of light years of the Solar System, and at that time it would have been one of the most brilliant objects in the skies of Earth.

Its path through space associates Gamma Microscopii with a collection of stars known as the Ursa Major Moving Group, stars whose trajectories through the Galaxy imply that they shared a common origin. Among the more prominent members of that group are most of the stars that make up the Plough (or Big Dipper), far to the north of Gamma Microscopii in the sky.