47 Tucanae is a brilliant southern globular cluster, shining beside the Small Magellanic Cloud but lying far closer, in our own Galaxy’s halo.
At a glance
| type | globular cluster |
|---|---|
| distance from the Sun | 14,700 light-years (4.5 kpc) |
| its light left it | 14,700 years ago |
| size in the piece | about 130 light-years acrossmodel |
Read off the piece’s own catalogue, the same values it draws with. Model marks a property of the piece’s galaxy model rather than a measurement.
About 47 Tucanae
A globular cluster is a dense ball of old stars orbiting in the Milky Way’s halo. 47 Tucanae is one of the brightest and most massive, surpassed in the sky only by Omega Centauri, and its core is unusually concentrated: stars are packed so densely there that close encounters between them are frequent.
Those encounters build exotic objects. Radio astronomers have found a large population of millisecond pulsars in the cluster, neutron stars spun up by gaining matter from a companion, and X-ray telescopes see many close binaries. It also has blue stragglers, stars rejuvenated by mergers or mass transfer.
On the sky it sits next to the Small Magellanic Cloud, but the two are unrelated: the cluster is a near neighbour inside our Galaxy, while the Cloud is a separate galaxy far beyond it.
What you see in the piece
From the Sun it is a fuzzy point near the Small Magellanic Cloud; pull back and the two separate at once, the cluster close by in the halo, the Cloud far out beyond the Galaxy.
Measured or modelled
The size drawn for the cluster is a modelled extent rather than a measured edge.
Questions
How far away is 47 Tucanae?
47 Tucanae is about 14,700 light-years (4.5 kpc) from the Sun, much closer than the Small Magellanic Cloud it appears next to.
Is 47 Tucanae part of the Small Magellanic Cloud?
No. It is a globular cluster of the Milky Way that happens to lie in the same direction as the Small Magellanic Cloud, which is a separate galaxy much farther away.