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Which globular clusters can be seen with the unaided eye?
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Globular cluster
Globular cluster M13.
While most globular clusters require a telescope to be observed, a few are visible to the unaided eye as faint, hazy patches of light. The most prominent examples include:12
- Omega Centauri: Located in the constellation Centaurus, this is the brightest globular cluster, with a magnitude of 3.7.31
- Messier 13: Found in the constellation Hercules, this is the best-known and easiest globular cluster to observe in the Northern Hemisphere.14
Additionally, 47 Tucanae—the second brightest globular cluster after Omega Centauri—is also noted for its visibility. Although these objects can be seen without optical aid, they were not formally recognized as star clusters until after the invention of the telescope.4512