Astronomy Picture of the Day - M13: The Great Globular Cluster in Hercules

NASA ^ | 14 Aug, 2025 | Image Credit & Copyright: R. Jay Gabany

[MtnClimber]

Explanation: In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent." Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster's hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core, upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison with our neighborhood of the Milky Way, the closest star to the Sun is over 4 light-years away. Early telescopic observers of the great globular cluster also noted a curious convergence of three dark lanes with a spacing of about 120 degrees, seen here just below the cluster center. Known as the propeller in M13, the shape is likely a chance optical effect of the distribution of stars viewed from our perspective against the dense cluster core.

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TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: apod; nasa

[MtnClimber]

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For more detail go to the link and click on the image for a high definition image. You can then move the magnifying glass cursor then click to zoom in and click again to zoom out. When zoomed in you can scan by moving the side bars on the bottom and right side of the image.

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[MtnClimber]

[x]

Is that the glob that is slowly making its way to New York City?

[MtnClimber]

Pinging the APOD list

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[BenLurkin]

Biig Badda-Boom

[GaltAdonis]

Does the cluster contain caramel and pecans?

If so, I’m all in.

[No name given]

Wow.

[Big Red Badger]

So That’s Where THEY are Hiding!
/$

[xp38]

The clusters seem to cluster around the galaxy core as this side view illustrates. They are certainly curiosities. One could say that about everything in the heavens though.

[telescope115]

I wonder what nighttime looks like to an inhabitant of o solar system in M13. It must be spectacular…

[blueunicorn6]

“Great Globular Cluster”

Try saying that three times fast.

[Diana in Wisconsin]

“Great Globular Cluster!”

We need to shout that whenever Congress screws up. *SMIRK*

[Verginius Rufus]

Yes, living on a planet orbiting a star in the M13 globular cluster would mean seeing a lot of bright stars at night. But would it make up for not having chocolate?

[Pete from Shawnee Mission]

Provided life can exist with all the energy from this compact grouping of stars, It might be that if you are in the center of the cluster you do not experience night because of all the ambient light!

[Romulus]

Like living in a microwave/x-ray machine. No inhabitants.

[telescope115]

I don’t know…chocolate is gooooood……..😛

[DannyTN]

M13 is #2 in the Hercules Constellation. Based on the location, i'd say it's either a swollen lymph node or an armpit tumor.