Hercules

The Strongman

A large summer constellation with a four-star Keystone and M13, the brightest globular star cluster in the northern sky.

Chart drawn as the sky looks when you face the constellation: north is up and east is to the left. Dot size shows brightness, and color hints at temperature. The connecting lines are one common stick figure; other traditions draw them differently.

Best season: Summer
Best months: May through September, high in the sky on summer evenings
Visibility: Visible from everywhere in the United States
Abbreviation: Her

How to find it

Look for the Keystone, a lopsided four-star square, between Vega and the arc of Corona Borealis.
M13 lies between the two stars on the Keystone's western side, closer to the upper one.

Brightest stars

Kornephoros (the brightest star in Hercules)
Rasalgethi (a red giant and double star)

What to look for

M13 as a fuzzy star in binoculars on a dark night.

Binocular and telescope targets

Great Globular Cluster (M13): hundreds of thousands of stars, the best globular cluster in the northern sky
M92: another bright globular cluster near the Keystone
Rasalgethi: a double star with a red giant and a blue-green companion

Using it to find other things

Hercules sits between Vega and Corona Borealis.

About this constellation

Hercules is a large constellation, but only the Keystone stands out. Start there, then look for M13.

Rasalgethi, which marks the strongman's head, is a red giant star. Its name comes from an Arabic phrase meaning 'head of the kneeler.'

Related guides

Visibility depends on your latitude, the date, and the time of night. The months above assume a typical evening from the contiguous United States, so use a planetarium app to confirm what is up tonight. Never look at the Sun through binoculars or a telescope without a proper solar filter.

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