The Caldwell Objects

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NGC5694
Type: Globular
Cluster
Con: Hydra
RA: 14 h 39 m 36.5 s
Dec:-26° 32' 18"
Mag: 10.2
Diam: 4.3'
Dist: 113,000 light-years
Disc: William
Herschel, 1784
W. HERSCHEL: [Observed
22 May 1784] Pretty bright,
small, nearly round, bright
in the middle, resolvable.
(Η II-196)
GC: Considerably bright, considerably small, round,
pretty suddenly brighter in the middle, resolvable, a
single star nearby.
NGC 5694 is THE FINAL OBJECT IN THE LATE Walter
Scott Houston's "Hydra Hysteria" — a deep-sky
romp through the sky's largest constellation that
was published first in Sky & Telescope and later in
his Deep-Sky Wonders book. Hydra spans nearly
100° and contains a cornucopia of splendors.
Houston designed the Hydra Hysteria challenge
to be "a little different" from the Messier
Marathon, for he wanted something that would
"sharpen the skills needed to star-hop to small
and faint galaxies as well as bright and easy
objects." In a way, Houston's Hydra Hysteria
mimics Hercules's second labor, which was to
conquer Hydra. That was no easy task, as the Sea
Monster had nine heads, and every time one was
cut off two new ones appeared in its place. But
Hercules prevailed; he knocked off eight of
Hydra's heads with a club and buried the ninth
NGC: Considerably bright, considerably small, round, pretty
suddenly brighter in the middle, resolvable, a star of magnitude
9.5 south preceding [to the southwest].
66
under a rock. I like to imagine NGC 5694 as this
ninth head, for it is buried in the extreme
northeastern corner of Hydra, under a southern
ledge of Libra and near a western wall of
Centaurus.
William Herschel first found NGC 5694 in
1784, but not until 1932 did Lowell Observatory's
Carl Otto Lampland and Clyde Tom-baugh
identify it as a globular cluster. At a distance of
113,000 light-years, the lOth-mag-nitude globular
is one of the most remote in the heavens. Its stars
are packed into a region 140 light-years wide.
Like M92 in Hercules, NGC 5694 is one of our
galaxy's oldest globu-lars. It is also far (95,000
light-years) from our galaxy's core. It's possible
the cluster formed in the inner halo of the galaxy,
only to be ejected into the outer halo by a close
passage of the Magellanic Clouds. McMaster
University as-
The Caldwell Objects 263