The Caldwell Objects

simply takes much too much effort to do so. So,
just as no single star in the Omega Centauri
cluster is Omega, nor is any star in the Jewel Box
Kappa.
The Jewel Box packs 281 known members
into an area only 10' (14 light-years) across. The
hypothetical inhabitants of a planet orbiting any
of the cluster's dimmer stars would have one of
the most glorious night skies
imaginable: four Rigel-like stars, each blazing
brighter than a quarter Moon, with hundreds of
other stellar companions projected against
luminous splashes of Milky Way and dark, dusty
voids. The light we see shining from these stars
today began its journey across space shortly
before the Syrians slew Ahab, King of Israel, at
Ramoth-Gilead.
In the May 1995 issue of the Astronomy and
Astrophysics Supplement, Ram Sagar estimates the
Jewel Box's age to be about 10 million years,
making the cluster a contemporary of the Double
Cluster in Perseus (Caldwell 14) and the Tau
Canis Majoris Cluster (Caldwell 64). After
sampling 813 of the region's stars,
94
some as faint as 20th magnitude, Sagar and his
colleagues determined that obscuring dust is not
uniformly distributed across the cluster's face.
On average, though, each of the cluster's stars is
dimmed by 0.4 magnitude (30 percent). The
cluster's stars formed nearly at the same time
from a molecular cloud that may have predated
the cluster by 6 or 7 million years or more. To
date nine Beta Cephei variables have been
discovered in the cluster.
To find the Jewel Box, look 1° southeast of
1st-magnitude Beta (β) Crucis, the eastern arm of
the Cross. The Jewel Box is visible to the naked
eye as a 4th-magnitude "star" even under the
light of a quarter Moon. Binoculars will bring out
four bright stars against a background of misty
light. The four bright stars form a tiny pyramid
— the triangular figure seen by Dunlop. (By the
way, if you doubt my claim that it would have
been difficult for our ancestors to resolve the
Jewel Box with the naked eye, give it a try. Its
two brightest members shine at 6th magnitude
and are separated by about 1.5'. I resolved these
two stars with effort from Zambia in June 2001.
And though it was not that difficult, I did have
the advantage of knowing what to look for.)
At 23x in the 4-inch (with south "up") the
cluster looks like an ice-cream cone. The bright
pyramid of stars is the cone; a faint sprinkling of
stars to the south and west is the ice cream; and a
roughly 1 lth-magnitude pair of stars is a fuzzy
cherry on top. The Jewel Box also looks like two
superposed clusters, one bright, one faint. Under
a direct telescopic gaze its brightest stars seem
chiseled out of black marble. Look with averted
vision at the 6th-magnitude sun in the
southeastern corner of the pyramid — the Yale
Kappa, or HD 111973 — and see if the area
around it doesn't sparkle with faint suns. That
star is the jewel at the center of a pendant-shaped
asterism of l0th-magnitude suns,
The Caldwell Objects 379