The Caldwell Objects

jewels. Here are sapphires, rubies, topaz, and
diamonds bursting out of treasure chests mired
in the black sands of a volcanic beach. Few of the
heavens' sights are better. A closer look with
higher magnification reveals a dark Y-shaped rift
at the heart of NGC 869, just east of the cluster's
elongated core. In comparison the core of NGC
884 resembles a hollow rib cage of stars
surrounding a ruby heart — the pulsating
semiregular variable star RS Persei. (The star's
pulse is slow, its magnitude varying between 7.8
and 10.0 about every 224 days.) The Millennium
Star Atlas shows a half dozen other variables in
and around the Double Cluster. Finally, near the
Double Cluster lies the
radiant of the Perseid meteor shower, which
peaks in the predawn morning hours of August
12th. Allen notes that Dante may have made reference
to the Perseid meteors in the Purgatorio:
Vapors enkindled saw I ne'er so swiftly
At early nightfall cleave the air serene,
Nor, at the set of sun, the clouds of August;
14
"In the Middle Ages," Allen continues, the
Perseids "were known as the Larmes de Saint
Laurent, Saint Laurence's Tears, his martyrdom
upon the red-hot gridiron having taken place on
the 10th of August, 258." Thus together with the
upwellings of starlight in the Double Cluster we
have tears of fire and ice.
The Caldwell Objects 67