skyandtelescope.com • SEPTEMBER 2019 35
two or three dark patches. Noted planetary nebula observer
Kent Wallace describes the inner dark patches as making
an S shape. The nickname Little Gem, also coined by Mal-
las, rightly belongs to this object although some references
apply the name to NGC 6445. According to Wallace, this was
originally due to an error in the Sky Catalogue 2000.0 that
was repeated often enough to have permeated through the
amateur community.
Planetary nebulae are important laboratories for the study
of stellar evolution, which only enhances their interest. It’s
astounding to think that life wouldn’t be possible without
the elements that planetary nebulae distribute throughout
the interstellar medium. And it may be that in observing
planetaries, we’re witnessing the end state of our Sun. It’s
currently not entirely clear whether or not our Sun will ever
become a visible planetary nebula. Recent research suggests
that binary interactions may be required to produce the sort
of bright complex objects like those on our tour. In any case,
the demise of our Sun will be similar, even if less spectacular.It’s astounding to think that life wouldn’t be possible without
the elements that planetary nebulae distribute throughout the
interstellar medium.
These beautiful and mysteri-
ous objects not only fore-
tell our future, but are an
essential component of the
process that led to our very
existence.¢ Contributing Editor TED
FORTE enjoys observing
planetary nebulae from his
home observatory in south-
eastern Arizona. He is the co-
ordinator of the Astronomical
League’s Planetary Nebula
Program.FURTHER READING: See the August 2018 issue of Sky & Tele-
scope for two articles on planetary nebulae: Ted Forte’s “Aquila’s
Gems” and Howard Banich’s “The Riddle of the Nebulae.”Favorite Planetary Nebulae
Object Nickname Constellation Mag(v) SizeCentral Star
Mag(v) RA Dec.
NGC 6543 Cat’s Eye Nebula Draco 8.1 20 ′′ 11.1 17 h 58.6m +66° 38′
NGC 7048 Cygnus 12.1 61 ′′ 19.1 21 h 14.3m +46° 17′
NGC 7008 Cygnus 10.7 86 ′′ 13.2 21 h 00.6m +54° 33′
NGC 6826 Blinking Planetary Cygnus 8.8 36 ′′ 10.4 19 h 44.8m +50° 32′
NGC 7026 Cheeseburger Nebula Cygnus 10.9 45 ′′ 14.2 21 h 06.3m +47° 51′
NGC 7027 Green Rectangle Cygnus 8.5 55 ′′ 16.2 21 h 07.0m +42° 14′
Campbell’s
Hydrogen Star
Cygnus 9.6 7 ′′ 11.3 19 h 34.8m +30° 31′NGC 6842 Vulpecula 13.1 57 ′′ 15.9 19 h 55.0m +29° 17′
NGC 6879 Sagitta 12.5 9 ′′ 14.8 20 h 10.4m +16 ° 5 5′
IC 4997 Sagitta 10.5 3 ′′ 14.4 20 h 20.1m +16 ° 4 4′
NGC 6905 Blue Flash Nebula Delphinus 11.1 72 ′′ 15.7 20 h 22.4m +20° 06′
NGC 6781 Aquila 11.4 114 ′′ 16.7 19 h 18.5m +06° 32′
NGC 7009 Saturn Nebula Aquarius 8.0 35 ′′ 11.5 21 h 04.2m –11° 22′
NGC 7293 Helix Nebula Aquarius 7.3 1054 ′′ 13.5 22 h 29.6m –20° 50′
NGC 6818 Little Gem Sagittarius 9.3 46 ′′ 16.9 19 h 44.0m –14° 09′
Sizes are from recent catalogs. Visually, an object’s size is often smaller than the cataloged value and varies according to the aperture and magnifi cation of the
viewing instrument. Right ascension and declination are for equinox 2000.0.pLITTLE GEM This Hubble im-
age of NGC 6818 clearly shows
how mass loss from dying stars is
an uneven process. Head over to
Sagittarius to take a peek at this
jewe l of a planetary nebula.ES
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