Which constellation is named after a reticle or eyepiece?

Which constellation is named after a reticle or eyepiece? Reticulum is named after the reticle, the crosshair grid used in a telescope eyepiece.

The constellation’s Latin name means “small net,” describing the fine mesh or network of lines used to measure the positions of stars. French astronomer Nicolas-Louis de Lacaille introduced the constellation in the eighteenth century while observing the southern sky from the Cape of Good Hope. He named it le Réticule Rhomboide in honor of the reticle in his telescope, and the name was later Latinized to Reticulum.

Reticulum is a small, faint constellation in the southern celestial hemisphere. It was not part of Ptolemy’s ancient list of 48 constellations, because it was created much later during the era of telescopic mapping. The International Astronomical Union officially recognized it as one of the modern constellations in 1922.

A common mix-up is Telescopium, another constellation connected with astronomical instruments. Reticulum refers specifically to the measuring grid or crosshairs inside an eyepiece, not to a complete telescope. It is best observed from October through December and is difficult to see from far northern latitudes.