Sextans

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Each new advance in technology brings a lot of quick converts -- and a few stubborn folks who prefer to stick with the old ways. An example of the latter was Polish astronomer Johannes Hevelius. In the late 17th century, he compiled the last major star catalog that was made without the aid of a telescope.

One of the constellations in his catalog was Sextans, the sextant. The faint constellation is low in the west this evening.

Hevelius watched the stars from a platform atop his house. During his prime skywatching years, just about every other astronomer was using a telescope. But Hevelius stuck with older instruments like a quadrant and a sextant. These instruments measured angles in the sky -- the angle between stars, for example, or the angle between a star and the horizon. Since they didn't have lenses, though, they didn't allow Hevelius to see anything that wasn't visible to the naked eye.

Even so, in 1687 Hevelius completed a star catalog and atlas. They included 10 new constellations, most of which were made from faint stars. The list included Sextans. It commemorated one of Hevelius's instruments, which had been destroyed in a fire.

Sextans is low in the west at nightfall. It's below Regulus, the brightest star of Leo, the lion, and the golden planet Saturn. Its stars are all quite faint, so you need a starchart to find them -- like the charts compiled with the eyes -- and the sextant -- of Johannes Hevelius.

Script by Damond Benningfield, Copyright 2009

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