The Hercules Family --- The Constellation of Sextans The Sextant

Sextans has a rather indeterminate asterism, and no bright stars. It stands out mostly because its area of the sky is surprisingly empty.

Seventh on our list of Hercules Family constellations is Sextans The Sextant, a dim modern constellation lying just to the south of Leo The Lion. Sextans has just one star brighter than the fifth magnitude, making it just barely visible to the naked eye in a very dark sky. 

Sextans was first described by Johannes Hevelius (1611-1687). Hevelius was a member of the minor Polish-Lithuanian nobility of the time, and was a senior member of the city council of Danzig (Gdansk), today in Poland. He was a master brewer as well, but his true passion was astronomy. He built an observatory atop his large home, from which he identified seven still-extant constellations, studied sunspots, identified four comets, documented the first observed nova later named CK Vulpeculae, mapped numerous features on the lunar surface, and was inducted into the Royal Society (British), listed as their first German member (Danzig being predominantly a German town, and Hevelius being a native speaker of German) but later recognized as their first Polish member as well. 

Hevelius and his wife Elisabeth (also an astronomer of note) using a quadrant to take observations.

Despite prodding from his friend Edmund Halley, Hevelius was the last astronomer of note not to use a telescope on a regular basis, though he had several impressive ones in his collection. In 1679, his home / observatory burned to the ground, destroying his library and instruments. Enjoying the patronage of the Polish-Lithuanian royalty, he quickly rebuilt and recovered many of his lost records, but the destruction saddened him. He named Sextans, discovered later that year, in memory of his lost astronomical tools.

Today, Sextans is notable as the home of the farthest distant, hence oldest, observable galaxy cluster, CL J1001+0220. In it, we can see young stars forming the first heavy elements (remember that observing deep sky objects means looking back in time). The cluster lies 11.1 billion light years from Earth --- and 11.1 billion years in the past.

The oldest known galaxy cluster with protostars forming, less than 4 billion years after the Big Bang.