Stars come in bunches. Of the over 200 globular star clusters that orbit the center of our Milky Way Galaxy, 47 Tucanae is the second brightest globular cluster, behind Omega Centauri. Known to some affectionately as 47 Tuc or NGC 104, it is only visible from Earth's Southern Hemisphere.

Visible light images show the central region of globular cluster 47 Tucanae is closely packed, with stars less than a tenth of a light-year apart. This Chandra false-color x-ray view of central...