Sky and Telescope - July 2016 - 32

The Eagle's Spots
In 1962, Beverly Turner Lynds signiﬁcantly extended
Barnard's work, making a close examination of the red
and blue plates from the National Geographic-Palomar
Observatory Sky Atlas (POSS I). Lynds analyzed plates
for the 879 ﬁelds covered by the sky survey, outlined the
regions of dark nebulosity, calculated the position for the
center of each cloud, and made visual estimates of the
opacity of each cloud, on a scale of 1 (least opaque) to 6
(most opaque). The Lynds Dark Nebulae catalog included
1,802 objects, including Barnard's ﬁnds.

The Dark Bird of Prey
While dark nebulae are numerous throughout the Dark
Rift region, let's start our night's journey in Aquila.
Moving across the Eagle's wingspan, from west to east,
we cross over the Great Rift to arrive at a pair of dark
nebulae considered exemplary of their class. Just 1°° west
of Gamma (γ) Aquilae (Tarazed), we'll ﬁnd Barnard
142 and Barnard 143. Together, B142 and B143 form
Barnard's E, a dark glyph etched on a starry background.

19h 30m

19h 00m

Dark Nebulae in Aquila
Object

¡
+15°

B142

c
AQUILA
a

B143 (LDN 694)
B127 (LDN 544)

t

B142-3

B129 (LDN 549)

LDN 673

+10°

B130 (LDN 542)

_

LDN
663

B132

+

B328

`

B135

+5°

e

B136

b

B133 (LDN 531)

d

B134 (LDN 543)

B138
0°

f

B139 (LDN 619)

LDN
582

27

B139

B137
B136

-5°

B328
LDN
B135 B132 548
B127, `
B129-30

h

Star magnitudes

B134

32

These are two of the easiest dark nebulae to spot, well
within reach of 10×50 binoculars. If you're new to this
dark hunt, they make good training targets (S&T: Sept.
2014, p. 45).
Follow Aquila's spine down (southwest) to the bird's
tail, where you'll ﬁnd a number of deﬁned dark nebulae,
including B127, B129, and B130, all just north of the
4th-magnitude star 12 Aquilae. A row of three 7th- to
8th-magnitude stars arcs between 12 Aql and Lambda
(λ), pointing to the noticeably red carbon star V Aql to the
southeast and B130 to the northwest. Look for the "empty
space" forming a rough L in the speckled star ﬁeld - you
may ﬁnd it just a bit easier to spot B127 than its neighbors.
B132 and B328 lie northeast of these inky pools. B132
forms an uneven, extended line; it might require more
aperture to see. Look for its spikiness ½° northwest of 15
Aql. B328 is truly a small dark spot - very opaque, but
only 4′ across. B135 and B136 ﬂoat 40′ and 58′ east of 15
Aql, respectively; they're easier to distinguish, particularly B135, which stretches some 13′ across.

2
3
4
5-10°
6
7

July 2016 sky & telescope

12

B133

B137
B138 (LDN 627)
LDN 548 (B113)
LDN 582 (B335)
LDN 663

Opacity

M26

SCUTUM

HH 32

RA

Dec.

40.0′

19h

39.7m

+10° 31′

30.0′

19h

41.4m

+11° 00′

4.5′

19h

01.5m

-05° 26′

5.0′

19h

02.1m

-05° 22′

5

16.0′

19h

01.9m

-05° 36′

6

8′ × 16′

19h

04.5m

-04° 25′

4.0′

19h

04.8m

-04° 14′

13.0′

19h

07.6m

-03° 55′

8.0′

19h

08.8m

-04° 00′

6

6.0′

19h

06.2m

-06° 54′

6

6′ × 3.5′

19h

06.9m

-06° 14′

5

11′ × 2′

19h

18.0m

-01° 27′

3

2.5′ × 1′

19h

16.0m

-01° 19′

2

140 × 140′

19h

14.0m

+00° 50′

60.0′

18h

49.6m

-03° 42′

30.0′

18h

52.6m

-01° 56′

6

6.0′

19h

36.9m

+07° 34′

6

10′ × 40′

19h

20.9m

+11° 15′

1.0′

19h

20.5m

+11° 02′

6
6
5
5

6
6
6

5
5

M11
LDN 673

Size

-

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.
Sky and Telescope - July 2016

Table of Contents for the Digital Edition of Sky and Telescope - July 2016
