The constellation of Sexans the Sextant is a modern creation. It was named by Johannes Hevelius in the 1600s. Hevelius named seven new constellations in his book titled Prodromus Astronomiae. The seven new constellations that Hevelius carved out of the dark patches of sky were Sextans, Canes Venatici, Lacerta, Leo Minor, Lynx, Scutum, and Vulpecula. Hevelius named one of his new constellations after the measuring device known as a sextant. Hevelius used a sextant instead of a telescope when he observed the stars.
How to Locate Sextans the Sextant
Sextans the Sextant is notable for what it lacks. It appears as a deep and dark empty patch of sky beneath Leo the Lion. This area is best observed in the spring in the Northern Hemisphere and its border begins just 6 degrees below the bright "foot" star Regulus in Leo. The brightest star in all of Sextans is a dim 4.48-magnitude light known as Alpha Sextantis. It lies about 287 light-years from Earth. Gamma Sextantis and Beta Sextantis are two 5th magnitude stars that complete the simple V-shape of Sextans the Sextant.
Deep-Sky Observing Targets in Sextans
Clusters and nebulae are scarce in Sextans. There are many galaxies that reside here, however, only one of these galaxies is brighter than 10th magnitude. This galaxy is NGC 3115. NGC 3115, also called the Spindle Galaxy, is located in the western portion of the constellation, not far from the constellation Hydra. The Spindle Galaxy is magnitude 9.19 and lies about 32 million light-years away. The Spindle Galaxy is a few times larger than the Milky Way Galaxy. The Spindle Galaxy is classified as a lenticular galaxy. Lenticular galaxies are galaxies that have characteristics of a spiral galaxy and an elliptical galaxy. Often these galaxies are seen edge-on, making it hard to determine if they are truly ellipticals or spirals.
William Herschel discovered the Spindle Galaxy on February 22, 1787. A recent discovery involving the Spindle Galaxy occurred in 1992, when researchers at the University of Hawaii and University of Michigan announced they found a supermassive black hole at the center of this galaxy. At about 2 billion times the mass of the Sun, it is one of the largest black holes known. The black hole was easy to find due to its large size compared to the rest of the galaxy. The ages of the stars show the Spindle Galaxy to be an older galaxy, and its black hole is no longer growing and consuming neighboring stars. NGC 3115 should not be confused with another NGC 5866, which is also known as the Spindle Galaxy but lies in the constellation Draco.
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