47 Tucanae (NGC 104)
|Left: Photo of the globular star cluster 47 Tucanae
taken with the Very Large Telescope, in Chile. Right: NASA/ESA Hubble
Space Telescope photo of the core of 47 Tuc. The bright orange-red
stars are red giants.
47 Tucanae is the second brightest globular cluster in the sky, after Omega Centauri. To the
unaided eye it looks like a misty star. Binoculars clearly show an increase
in brightness toward the center and a telescope with an aperture of at least 10 cm resolves some of the roughly one million member stars.
Although a conspicuous naked-eye sight, 47 Tucanae (NGC 104) lies so far
south, in the constellation Tucana, that it
wasn't discovered by astronomers until 1751 when Nicholas de Lacaille catalogued it in his list of southern nebulous objects.
|Hubble Space Telescope image of stars near the center
of 47 Tuc
A search for Jupiter-like planets in 47
Tuc, carried out by an international team of astronomers using data from
the Hubble Space Telescope, came up empty-handed.
The work involved checking 34,000 stars in the cluster for signs of large
transiting planets. The absence of any positive results strengthens the
argument that planets are rare or nonexistent in globular clusters because
of the very low concentration of heavy elements.
||31' (about the size of the full moon)
||13,400 light-years (4,100 pc)
||R.A. 0h 24m 05.7s,
Dec. -72° 04' 53"
AND STAR CLUSTERS