The Caldwell Objects

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for detecting the galaxy with a 4-inch telescope
and 27x for doing so with an 8-inch.
To find NGC 4236, first locate 2ndmagnitude
Beta (β) Ursae Minoris (Kochab) and
Alpha (α) Ursae Majoris (Dubhe), then look for
4th-magnitude Kappa (κ) Draconis roughly
halfway between them; Kappa is the brightest
star in a tight chain of three. The galaxy is 1½° to
the west-southwest of Kappa Draconis. Light
pollution will greatly diminish your chances of
seeing this dim but intriguing object. If you do
locate it, keep in mind that the ghostly glow you
are beholding is a vast island universe measur-
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ing 34,000 light-years in diameter, with a total
mass of 6.6 billion Suns. NGC 4236 is receding
from the Milky Way with a cosmo-logically
negligible velocity of only 2 km per second. This
means that local galaxy dynamics and the Sun's
motion within the Milky Way have negated the
redshift that one would expect the universe's
expansion to impart to a galaxy 7 million lightyears
distant.
If you're looking for more of a challenge, try
spying the tiny 12th-magnitude galaxy NGC
4128, only 1° southwest of NGC 4236. NGC 4128
has a bright stellar core surrounded by a dim,
slightly elliptical halo.
Deep-Sky Companions: The Caldwell Objects