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Star clusters

Globular cluster 47 Tucanae: size, dimension and comparison

The adopted reference is about 120 light-years.

cluster extent ≈ 120 ly

A light-year is a distance: how far light travels in one year. It is used for distances between stars.

A concentration of stars larger than a planetary nebula.

Explore at this scale
Globular cluster 47 Tucanae, interpreted illustration
Interpreted illustration · dimension stated in the fact sheet.

What does this number measure?

NASA gives about 120 ly for the whole cluster in a context view. The small rectangle of the Hubble close-up is not the size of the entire cluster.

Compare the stated dimensions

The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.

Compare with Hercules Cluster · M13 in the explorer →

Source and limitations

Rounded documentary extent. Boundaries are diffuse and depend on the observations and convention used; this is not a distance from Earth.

Original schematic illustration, not a photograph. Shapes, colours and details are interpreted; only the stated dimension is compared.