Astronomy

arm is also warped from a tidal interaction with

12th-magnitude NGC 4747, roughly 30' to its north-

east. In images, NGC 4747 displays three tidal tails,

all of which have resulted from the gravitational

encounter with its superior neighbor.

Let’s now run our visual comb 4 ̊ south-southeast

to 35 Comae Berenices — an understated triple star

whose primary components are a great resolution

test for a 4-inch telescope. The closest pairing con-

sists of a 5th-magnitude pale yellow primary and a

colorless magnitude 7.5 secondary 1" to its southeast.

The third component is a 9th-magnitude blue gem

29" farther to the southeast. (A 1 ̊ swing will bring

you to the famous Black Eye Galaxy, M64. Can you

see the pale blue hue of the galaxy’s disk appearing

like milk residue on a glass?)

Hair extensions

If we extend the eastern tress 5 ̊ farther to the south-

east from 35 Com, we arrive at the constellation’s

Alpha [α] star, Diadem, and the magnificent globular

star cluster M53 just 1 ̊ to its east-northeast. This

glorious cluster belongs to the Sagittarius tidal

stream — the tidal tail of the Sagittarius dwarf sphe-

roidal galaxy, of which globular star cluster M54 in

Sagittarius is the nucleus. But the elusive object in

this region is the 10th-magnitude ghost globular

NGC 5053, which looms like an ashen spirit about 1°

southeast of M53. It’s a challenging object for

city observers and small telescopes, because the

dim light is almost uniformly spread across nearly 11'

of sky with little central concentration. Even its

brightest stars evade the casual gaze, as they shine

around 14th magnitude. Nevertheless, this phantom

wears several superlatives, including being the most

metal-poor and least concentrated globular cluster

known.

Let’s move over now to the constellation’s middle

tress. A lovely sight in itself, the gentle southward

f low of stars follows Gamma, 14, 16, 17, 21, 23, and

26 Com before a kink extends it southwestward to

24 Comae Berenices. Stop here, because 24 Com is

the binary gem of the constellation. Any size tele-

scope at any power will show the amazing color con-

trast. I see a golden 5th-magnitude primary with a

sea green magnitude 6.5 companion 20" to the west;

others see the pair as yellow and blue. The stars are

strikingly reminiscent of Albireo in Cygnus the

Swan. What usually goes unnoticed in this scene is

the challenging 3'-long spindle of the near edge-on

12th-magnitude barred spiral galaxy NGC 4539,

which lies only 15' southwest of 24 Com.

Another kink carries the tress 3 ̊ southeast

of 24 Com to 5th-magnitude 27 Com. Center that

star and look about 45' to the west-southwest

for the 11th-magnitude NGC 4651, the amazing

The Umbrella Galaxy

(NGC 4651) is visible

through small telescopes.

Medium-sized instruments

show the galaxy’s faint

tidal tail, which is the

result of an encounter

with a small interloping

galaxy. R. JAY GABANY

The Umbrella

Galaxy displays a

crescent-shaped

structure

extending

laterally from

an enormous

jet that seems

to emanate

from the

galaxy’s heart.