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The Caldwell Objects

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4 7<br />

NGC 6934<br />

Type: Globular Cluster<br />

Con: Delphinus<br />

RA: 20 h 34 m 11.6 s<br />

Dec: +07° 24' 15"<br />

Mag: 8.8<br />

Diam: 7.1'<br />

Dist: 57,000 light-years<br />

Disc: William Herschel,<br />

1785<br />

W. HERSCHEL: [Observed 24 September 1785] Very<br />

bright, large, gradually much brighter in the<br />

middle.<br />

GLOBULAR CLUSTERS ARE THE MILKY WAY'S<br />

senior citizens. When our galaxy was an adolescent,<br />

some 10 to 16 billion years ago, thousands<br />

of globulars are thought to have formed<br />

from its original allotment of gas. <strong>The</strong> clusters<br />

may even have begun life as the cores of dwarf<br />

galaxies. In time, though, most of these primordial<br />

clusters perished in repeated, tragic<br />

encounters with each other or with the galac-<br />

<strong>The</strong> <strong>Caldwell</strong> <strong>Objects</strong><br />

Easily resolvable. Beautiful object. (Η I-103)<br />

GC: Globular, bright, large, round, well resolved, clearly<br />

consisting of stars, stars of the 16th magnitude downwards, star<br />

of the 9th magnitude preceding [to the west].<br />

NGC: Globular, bright, large, round, well resolved, clearly<br />

consisting of stars, stars of 16th magnitude and fainter, star of<br />

9th magnitude preceding [to the west].<br />

47<br />

tic center. Today, only about 150 globulars — the<br />

remnants of the largest dwarf galaxies? — are<br />

known to have survived these ravaging<br />

encounters. Delphinus, the small but illustrious<br />

celestial Dolphin, harbors two of these ancient<br />

galactic relics, and they are nearly cosmic twins:<br />

NGC 7006 (<strong>Caldwell</strong> 42) and NGC 6934<br />

(<strong>Caldwell</strong> 47).<br />

<strong>The</strong>se <strong>Caldwell</strong> clusters are separated by<br />

187

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