Sky and Telescope - June 2016 - 55

Sue French

NGC 5427
NGC 5569
NGC 5560

NGC 5426
NGC 5566

BOB FRANKE

ADAM BLOCK / MOUNT LEMMON SKYCENTER / UNIVERSITY OF ARIZONA

Sue French welcomes your comments at scfrench@nycap.rr.com.

Left: Deep-sky images show a starry bridge forming between interacting spiral galaxies NGC 5426 and NGC 5427. Right: The elongation of NGC 5560 suggests that it belongs to an interacting galaxy trio including NGC 5566 and NGC 5569. This LRGB image, taken
with a 12.5-inch f/9 Ritchey-Chrétien, highlights the dusty arms of NGC 5566 but also reveals the tight blue spiral of NGC 5569.

may ﬁnish their waltz, wheeling past each other in their
cosmic ballroom, or their mutual attraction might eventually pull them together, wedding these galaxies into
one vast system. If that's not enough to stir your soul,
ponder this: our Milky Way Galaxy and the Andromeda
Galaxy may take up this same stately dance a few billion
years from now. You could be previewing our future.
On the way to our next set of galaxies, let's pay a
visit to Phi (φ) Virginis, a close double star with very
unequal components, magnitudes 4.9 and 10.0. In
my 105-mm scope they're separated at 122×, the faint
attendant sitting east-southeast of its bright, golden
primary. The dimmer star appears orange when viewed
with my 10-inch scope at 166×. The primary star itself is
suspected of being a very close binary. As stars go, this
double or possibly triple system is relatively close to us at
about 135 light-years.
Continuing our northward trek, we'll visit two galaxy
triplets centered 5.2° east-northeast of Tau (τ) Virginis. Both groups can share a low-power ﬁeld with the
7.0-magnitude star to their west, HD 125309.
The southern triplet consists of NGC 5576, NGC
5574, and NGC 5577, in order of increasing diﬃculty.
The ﬁrst two can be spotted in the 105-mm refractor. At
28× NGC 5576 is a faint, very small oval that makes a
12.5′-tall right triangle with two 10th-magnitude stars,
one northwest and the other west-southwest. At 87×
the galaxy is considerably easier to see, showing oﬀ
a brighter center within an east-west oval. At 122× it
reveals a stellar nucleus. Sitting 2.8′ southwest, NGC

5574 is faintly visible with averted vision, and it's elongated almost parallel to the 10th-magnitude stars.
Through the 10-inch reﬂector at 115×, NGC 5576 has a
faint, 2′ × 1′ halo surrounding a brighter, round core and
a nearly stellar nucleus. A 13th-magnitude star rests 1.2′
northwest of the galaxy's center. NGC 5574 looks considerably smaller, a little more than 1′ long and perhaps
25″ wide, and it grows gently brighter toward the center.

Finding the Galactic Fluﬀ
Object

Mag(v)

Size/Sep

NGC 5427

11.4

NGC 5426

Dec.

2.8′ × 2.4′

14h

03.4m

-6°° 02′

12.1

3.0′ × 1.6′

14h 03.4m

-6° 04′

φ Virginis

4.9, 10.0

5.3″

14h 28.2m

-2° 14′

NGC 5576

11.0

3.5′ × 2.2′

14h 21.1m

+3° 16′

NGC 5574

12.4

1.6′ × 1.0′

14h

20.9m

+3° 14′

NGC 5577

12.3

3.4′ × 1.0′

14h 21.2m

+3° 26′

NGC 5566

10.6

6.6′ × 2.2′

14h 20.3m

+3° 56′

NGC 5560

12.4

3.7′ × 0.7′

14h 20.1m

+4° 00′

NGC 5569

13.2

1.7′ × 1.4′

14h

20.5m

+3° 59′

NGC 5701

10.9

4.3′ × 4.1′

14h 39.2m

+5° 22′

Angular sizes and separations are from recent catalogs. Visually, an object's size is often
smaller than the cataloged value and varies according to the aperture and magniﬁcation of the
viewing instrument. Right ascension and declination are for equinox 2000.0.

Sk yandTelescope.com June 2016

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Sky and Telescope - June 2016

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