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M30

Jellyfish Cluster

GlobularCluster Capricornus Mag 7.2

Object Data

Catalog Designation
M30
Type
GlobularCluster
Constellation
Capricornus
Magnitude
7.2
Right Ascension
21h 40m 22.1s
Declination
-23° 10' 47.5"
Distance
27,100 light-years
Angular Size
11.0
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About M30

Description

M30 is a compact globular cluster in Capricornus, about 26,100 light-years from Earth. It has undergone core collapse, giving it an extremely dense central region. The cluster spans about 93 light-years and contains several hundred thousand stars estimated to be 12.9 billion years old.

Observing Tips

Located about 3.5 degrees southeast of Zeta Capricorni. One of the last Messier objects to rise in autumn. In binoculars it appears as a small, bright fuzzy spot. A 4-inch telescope shows a bright, strongly concentrated core. An 8-inch telescope at high power resolves stars in the outer halo while the core remains an intense blaze. Best observed from August through October; it sets early, so observe soon after dark.

History

Discovered by Charles Messier on August 3, 1764. He described it as a round nebula without stars. Like M15, it is one of the few globular clusters known to have undergone core collapse.

Fun Facts

M30 is one of about 20 globular clusters known to have undergone core collapse — a gravitational runaway that compresses the core to extreme densities. The collapsed core has produced many blue stragglers through stellar collisions and mergers. M30's orbit takes it on a retrograde path around the Milky Way, suggesting it may have been captured from a dwarf galaxy.

Community Photos (1)

Credit: NASA/ESA. License: Public domain. (Wikimedia Commons)

Credit: NASA/ESA. License: Public domain. (Wikimedia Commons)

Skybred Feb 28, 2026