Which constellation is named after a pendulum clock?

Which constellation is named after a pendulum clock? Horologium is the answer.

Horologium is named after a pendulum clock, represented by a faint group of stars in the southern celestial hemisphere. The Latin word horologium means clock and ultimately derives from the Greek term for a timekeeping instrument.

French astronomer Nicolas-Louis de Lacaille introduced the constellation in 1756 after surveying the southern skies from the Cape of Good Hope. He depicted it as a clock with a pendulum and a seconds hand, reflecting the scientific instruments and tools that inspired many of his new southern constellations. The IAU later retained Horologium as one of the 88 modern constellations.

Horologium is easy to confuse with other instrument-themed constellations, including Norma, the carpenter’s square; Fornax, the furnace; and Antlia, the air pump. Its brightest star is Alpha Horologii, an orange giant. The variable star R Horologii can change dramatically in brightness, making it one of the constellation’s most interesting observing targets.