Sky & Telescope - June 2020 - 29

sources of light pollution. This means that urban imagers
equipped with narrowband ﬁlters will be rewarded with colorful results and rich details despite their bright skies.
Regardless of your sky's darkness, if you are using a monochrome camera, narrowband ﬁlters are a good option for imaging Sharpless objects. Hydrogen-alpha provides the predominant signal for most Sharpless objects, so imaging through
an Hα ﬁlter is beneﬁcial and can give you great results on its
own or combined with O III- and S II-ﬁltered images. Plan on
gathering plenty of exposures for the particularly dim nebulae
in the catalog - that will give you the best chance of revealing the faintest structures that your gear and sky conditions
will permit. You can even achieve good narrowband images of
bright emission nebulae under a gibbous Moon.
Extended nebulae in the catalog are best imaged with shortfocal-length instruments combined with a large sensor. Shoot
the faintest targets on the most transparent, Moon-free nights.
Conversely, longer focal lengths are helpful for the smaller

targets. For objects that contain small-scale detail, nights of
good seeing will produce the most satisfying results.

Additional Information
This article barely scratches the surface of this wonderful
resource. If you'd like to delve deeper into the Sharpless catalog, perhaps the best place online today is Dean Salman's The
Best of the Sharpless Catalog at sharplesscatalog.com. There
you'll ﬁnd a list of all 313 objects and their J2000 coordinates, as well as Dean's images of many Sharpless objects
taken through color and narrowband ﬁlters.
Whether you prefer imaging showpiece targets or like
to hunt for obscure treasures, think about consulting the
Sharpless catalog. This comprehensive list of objects reveals the
rich distribution of nebulosity within the Milky Way.

¢ By night, RON BRECHER is a deep-space imager residing in
Guelph, Ontario. Visit his website at astrodoc.ca.

Select Nebulae of the Sharpless Catalog
Object
Sh 2-49

Common Name
M16

Sh 2-54
Sh 2-98

Constellation

Size

Serpens Cauda
Serpens Cauda

RA

Dec.

35′ × 28′

18h

19m

-13° 58′

60′ × 30′

18h 18m

-11° 40′

59m

+31° 25′

00m

+35° 17′
+30° 55′

Cygnus

15′

19h
20h

Sh 2-101

Tulip Nebula

Cygnus

18′ × 10′

Sh 2-103

Veil Nebula

Cygnus / Vulpecula

210′

20h 51m

Sh 2-105

NGC 6888

Cygnus

18′ × 13′

20h 12m

+38° 21′

Sh 2-117

NGC 7000, NGC 5068

Cygnus

240′

20h 55m

+44° 13′

Sh 2-119

LBN 400

Cygnus

160′

21h 18m

+43° 56′

21h

Sh 2-124

38m

+50° 21′

Cygnus

70′

Sh 2-129

Flying Bat Nebula

Cepheus

110′ × 100′

21h 12m

+59° 57′

Sh 2-131

IC 1396

Cepheus

170′ × 140′

21h 39m

+57° 30′

Sh 2-155

Cave Nebula

Cygnus

50′ × 30′

Sh 2-157

Lobster Claw Nebula

Cassiopeia

90′

23h 16m

Sh 2-162

Bubble Nebula

Cassiopeia

15′ × 30′

23h 21m

+61° 12′

Sh 2-205

Peanut Nebula

Camelopardalis / Perseus

100′ × 30′

03h 56m

+53° 12′

Auriga

120′

05h 02m

+46° 21′

05h

42m

+36° 12′

Sh 2-221
Sh 2-232

Jelly Donut Nebula

Sh 2-235
Sh 2-244

Crab Nebula, M1

22h

57m

+62° 37′
+60° 02′

Auriga

40′

Auriga

7′ × 5′

05h 41m

+35° 51′

Taurus

6′ × 4′

05h

35m

+22° 01′

06h

17m

+22° 47′

06h 20m

+23° 16′

35m

-04° 52′

Sh 2-248

IC 443

Gemini

50′ × 40′

Sh 2-249

IC 444

Gemini

8′ × 4′

Sh 2-279

NGC 1977

Orion

20′ × 10′

05h

Sh 2-281

Orion Nebula

Orion

65′ × 60′

05h 35m

-05° 27′

08h

+08° 55′

Sh 2-290

Abell 31

Cancer

17′

54m

Angular sizes and separations are from recent catalogs. Right ascension and declination are for equinox 2000.0.

sk yandtelescope.org * JUNE 2 02 0

29
http://www.sharplesscatalog.com http://astrodoc.ca/ http://www.skyandtelescope.org
Sky & Telescope - June 2020

Table of Contents for the Digital Edition of Sky & Telescope - June 2020
