Hercules Cluster
Where is the Hercules Cluster?
Look west, about 50° up at 20:20 in Hercules. It sinks lower through the evening and sets at 03:29.
- Rises
- 05:58
- Highest
- 16:45
- Sets
- 03:29
- Best after dark
- 20:20 · 50°
Can I see the Hercules Cluster tonight?
From London tonight, the Hercules Cluster is above the horizon after dark. It’s highest soon after dark, around 20:20, in the west at 50°.
At magnitude 5.8, with its light spread out, it needs binoculars and a dark sky.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does the Hercules Cluster look like?
Eyes
Under dark skies, a faint fuzzy star on the side of the Keystone.
Binoculars
A small, round glow, brighter in the center.
Telescope
A stunning ball of stars. At 150 mm and above, stars resolve to the core, with curving chains of stars around it.
About the Hercules Cluster
M13, the Great Globular Cluster in Hercules, is the best-known globular cluster in the northern sky. It is a ball of several hundred thousand stars, more than 20,000 light-years away.
Its stars are ancient, about 12 billion years old, among the oldest in the Milky Way.
In 1974 a radio message was beamed toward M13 from the Arecibo telescope as a demonstration. It will take more than 20,000 years to arrive.
M13 was discovered by Edmond Halley in 1714. It is about 150 light-years across, and near its center stars are packed hundreds of times more closely than near the Sun.
Large telescopes sometimes show three dark lanes in M13, nicknamed the Propeller. Half a degree away lies the faint galaxy NGC 6207, millions of light-years beyond the cluster.
Hercules is high overhead on summer evenings from mid-northern latitudes, so M13 is easy to find in the months when nights are short.
Nearby in the sky
Questions
Can I see M13 with binoculars?
What was the Arecibo message?
Sources: SkyMate; OpenNGC (CC BY-SA 4.0); star chart: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences