SEXTANS (The Sextant) pronounced SEX-tanz

Chart showing Sextans

Sextans was formed by Hevelius the astronomer about 1680 in honour of the observatory instrument he had used since 1658 to observe star positions. It is not named after the nautical sextant, because that was invented by Hadley in 1730, well after the constellation was named. Hevelius continued to use his sextant for making unaided eye sightings of star positions long after telescopes were available.

It is a faint constellation with little to distinguish it. To find it look to the north in the evening above Regulus in Leo the Lion and below and to the right of Alphard, the heart of Hydra the Water Snake. The head of Hydra, which is easily made out, is to the left of Sextans.

Chart showing Sextans as seen to the north at about 9 pm (NZST) mid April.

Sextans constellation

Constellation Puppis Constellation Pyxis Constellation Hydra Constellation Crater Constellation Virgo Constellation Leo Constellation Cancer

Details of some of the objects shown in the chart.

α Sextantis is a magnitude 4.5 white star 287 light years away.

β Sex is a magnitude 5.1 blue-white star 345 light years away.

γ Sex is a magnitude 5.1 white star 262 light years away.

δ Sex is a magnitude 5.2 white star 300 light years away

NGC 3115 is a 10th magnitude edge on lenticular galaxy looking like a bright pointed spindle, from which it takes its popular name "The Spindle Galaxy". Moderate sized amateur telescopes show its elongated outline and brighter centre. It lies about 30 million light years away.


The constellation Sextans straddles the celestial equator, with α Sex being less than half a degree south of it. From New Zealand the constellation is due north and highest at about 12 pm (NZDT) at the beginning of April 1 and 8 pm (NZST) at the end of April.

By the end of July that the constellation gets lost in the evening twilight.