Sky & Telescope - July 2020 - 55

18h 30m

18h 20m

-30°

6624

18h 10m
6528

6522

SAGITTARIUS
6558
6569

-32°

-34°

RS
h5036

Star magnitudes

M69

6563

2
3
4
5
6
7
8

tipped about 60° east of north. There's
a slightly brighter arc along the northern edge and a more subtle brightening
on the opposite rim.
Farther north in Sagittarius, the
planetary NGC 6445 sits 22′ northnortheast of the globular cluster NGC
6440. Even at 17× in my little refractor, NGC 6440 is an easily visible,
little hazy patch 1.8° northeast of the
pale-yellow star 58 Ophiuchi. At 47×
the planetary nebula joins the scene
as a small, fairly faint spot with the
wide double star h2810 about 5′ to its
east. The double has a 7.6-magnitude
primary with a 10.4-magnitude companion a bit west of south. At 87× NGC
6445 is about 40″ long, roughly oval,
and leans north-northwest. The northnorthwestern edge appears brighter and
has a faint star a short distance beyond.
The globular cluster still shares the ﬁeld
of view. It spans 2.3′ and grows much
brighter toward the center. NGC 6440
adorns the middle of an 11½′-long line
of 11th- and 12th-magnitude stars, two
to the cluster's north-northwest and
two off the opposite side.
Arizona amateur Frank Kraljic says
that through his 10-inch reﬂector at
112×, NGC 6445 resembles a slightly
top-heavy, hollowed-out, rectangular
box. The northern and southern walls
are distinctly brighter, with the former
shorter but more intense. There are

hints of faint extensions reaching out
from the perimeter of the nebula. Kraljic
tells me that an O III ﬁlter worsens the
view, but a narrowband ﬁlter enhances
contrast of the planetary's walls. In
addition, he ﬁnds NGC 6445's interior
to be darker in its northern half.
Next, we'll move northward to
Lyra, where the planetary nebula NGC
6765 resides with its neighbor Messier
56, a globular cluster. Let's start with
M56, which is brighter and reasonably straightforward to locate 1.7°
west-northwest of the star 2 Cygni.
Even with my 15×45 image-stabilized
binoculars, M56 is an easily noticeable hazy patch with a broadly brighter
center and a faint star off the western
side. The cluster is quite pretty through

my 105-mm refractor at 87×. Its 1¾′
core is mottled, bright, irregular, and
surrounded by a star-spattered halo
that fades away near the western star.
A magniﬁcation of 127× pulls out a few
stars in the core. My 10-inch scope at
166× shows an irregular, partly resolved
core and a nice mixture of faint to fairly
bright stars scattered across the cluster.
A 6th-magnitude orange star lies

NGC 6445

u Visible even in small telescopes, NGC 6445
shares the field in low-power views with the
brighter globular cluster NGC 6440 just 22′ to
its south-southweest.

18h 00m

M23 6445

17h 40m
B83a

3
4
6568
5
6
7
8
6544

-20°

h2810

6537
Star magnitudes

NGC 6563: A DA M BLOCK / M OUN T LEM M ON
SK YCEN TER / UNIV ERSIT Y OF A RIZON A; NGC 6 445
A ND NGC 6 440: MIK E SIDONIO

p Left: A short star-hop from Kaus Australis, the southernmost star in the Sagittarius Teapot asterism, will lead you to the interesting planetary nebula
NGC 6563 floating in a rich star field. North is up in this 8′-wide view.

6440

B84

SAGITTARIUS

M21
M20 =
Trifid Nebula
M8 =
Lagoon Nebula

6401

NGC 6440

-24°

s k y a n d t e l e s c o p e . o r g * J U LY 2 0 2 0

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Sky & Telescope - July 2020

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