When is the best time to observe Lesath?

Lesath is best observed from May through July, with peak visibility during June when it transits around midnight in the Northern Hemisphere.

Where is Lesath located in the sky?

Lesath lies in the constellation Scorpius at right ascension 17h 31m and declination -37° 18′.

What telescope do I need to see Lesath?

At magnitude 2.7, Lesath is visible to the naked eye from dark skies, easy in any binoculars.

Lesath — Star in Scorpius

HIP 85696; Upsilon Scorpii; 34 Scorpii

Magnitude 2.7^m Star Scorpius (Sco) Visible

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About Lesath

Description

Lesath is a blue subgiant of spectral type B2IV at magnitude 2.69 in Scorpius. Located about 580 light-years from Earth, it is a hot star with a surface temperature of roughly 22,000 K and a luminosity about 12,300 times solar. Lesath sits at the very tip of the Scorpion's tail, forming a striking close pair with neighboring Lambda Sco (Shaula).

Observing Tips

Lesath is found at the end of the Scorpion's curved tail, immediately adjacent to the brighter Shaula (Lambda Sco). Together they form a conspicuous naked-eye pair sometimes called the 'Cat's Eyes' of the scorpion. The pair is best observed from June through August when Scorpius is prominent in the southern evening sky. From mid-northern latitudes, they are very low on the southern horizon.

History

The name Lesath comes from the Arabic 'las'a,' meaning 'sting,' aptly describing its position at the scorpion's stinger. Lesath and Shaula together have been recognized as the scorpion's sting since Babylonian times. In Chinese astronomy, the pair was called 'the Tail' of the Azure Dragon.

Fun Facts

Despite appearing as a close pair, Lesath and Shaula are not a true binary system — Lesath is about 580 light-years away while Shaula is roughly 570 light-years, so they are separated by a few light-years in actual space. Their close alignment as seen from Earth is largely a line-of-sight coincidence.