Categories: Astronomy ListsDeep-Sky Objects

Nebulae Named After Birds

Parrot's Head Nebula in Monoceros

With this list, we present a few nebulae of various types that are said to resemble birds, and while some of the structures mentioned do actually resemble some of our feathered friends, others do so only in the minds of observers armed with powerful imaginations. Nonetheless, all of the nebulae on this list are spectacular, with their formations representing brief, frozen moments in the long evolutionary history of the Universe.

In fact, nebulae as a whole are amongst the most elaborate structures in the universe, and come in an intriguing   array of morphologies, including ones that resemble land and aquatic animals, insects and even scary creatures, such as ghosts and ghouls. Whether you are able see the same birds that their namers originally identified in the nebulae hardly matters, though: what is important is that these nebulae represent the birth, lives, and eventual deaths of stars, and that our Sun will one day look like some of these nebulae on this list.

However, that is along way into the future, which means that in the meantime, we can start our tour of the cosmic aviary.

Robin’s Egg Nebula

Image Credit: Adam Block/Mount Lemmon Sky Center / University of Arizona

-Nebula type: Planetary nebula
-Constellation: Fornax
-Coordinates: RA 03h 33m 14.646s|Dec. -25° 52′ 18.214″
-Distance: 1,145 – 1,794 light years
-Apparent Diameter: 11.0 × 7.5 minutes of arc
-Magnitude: 9.4
-Other designations: PK220-53.1, ESO 482-PN007, AM 0331-260, GC 5315, PN G220.3-53.9

Although this nebula has long been known, its true nature as a planetary nebula was only confirmed comparatively recently when it was discovered that its central star is a long period, double degenerate binary system.

The binary nature of the central star itself was only confirmed in 2017, and it consists of a 0.555-solar mass star that is orbited by a 0.70-solar mass white dwarf over a period of 142 days. The faint, reddish tint of the darker cloud of material seen near the centre of the nebula is believed to be material that was ejected by the primary star in the system just before it collapsed.

Pelican Nebula

Image Credit: Miodrag Sekulic

-Nebula type: Combined emission nebula and HII region
-Constellation: Cygnus
-Coordinates: RA 20h 50m 48.0s|Dec. +44° 20′ 60.0″
-Distance: 1,800 light years
-Apparent Diameter: 60 x 50 minutes of arc
-Magnitude: 8.0
-Other designations: IC 5070, IC 5067

The shape of a pelican is clearly visible in this nebula, which is associated with, and separated from the larger North American nebula by a dark lane of dense molecular dust to the left of the Pelican’s head.

The Pelican nebula is one of the most intensely studied nebulae because it offers astronomers a snapshot of the processes in which young, energetic stars are slowly transforming cold clouds of neutral gas into hot, ionized gas. While the ionization front is expanding outward, particularly dense spires, globules, and columns of cold gas is resisting the process, which is slowly changing the appearance of the nebula.

Eagle Nebula

Image Credits: ESO

-Nebula type: Star forming region (HII region)
-Constellation: Serpens
-Coordinates: RA 18h 18m 48s|Dec. -13° 49″
-Distance: 7,000 light years
-True Diameter: 140 × 110 light years
-Magnitude: 6.0
-Other designations: Messier 16, NGC 6611, Sharpless 49, RCW 165, Gum 83, Star Queen Nebula

This nebula can be envisioned as an eagle with its talons extended, swooping down on its prey. The small, dark area seen at  the center of the image is better known as the Pillars of Creation, some detail of which is shown in the image below. While this photo shows only the tips of the Pillars, each pillar is about one light long, and contains many stars in the process of forming. In fact, the entire region surrounding the Pillars is a huge star-forming region that contains an open cluster of stars that can be seen as the bright blue spots in the image on the left, as well as several other star-forming regions that are not shown here.

In 2007, the Spitzer Space Telescope detected hot gas and dust that suggested a supernova event had occurred between 8,000 and 9,000 years ago close to the Pillars, whose light would have reached Earth between 1,000 and 2,000 years ago. Based on the Spitzer data, the supernova could have destroyed the Pillars about 6,000 years ago, but if it did, evidence of the event will only reach Earth in another 1,000 years or so, due to the vast distance involved.

Nonetheless, the Spitzer data is being disputed by some investigators, who argue that a supernova would have created more radio and X-ray radiation than had been observed, and that several nearby hot stars could have heated the gas of the pillars, instead. Future generations of astronomers will have to decide the issue when the light of the putative supernova arrives.

Owl Nebula

Image Credit: Keith Quattrocchi

-Nebula type: Planetary nebula
-Constellation: Ursa Major
-Coordinates: RA 11h 14m 47.734s|Dec. +55° 01′ 08.50″
-Distance: 2 030 light years
-Diameter: 1.82 light years
-Magnitude: 9.9
-Other designations: M97, NGC 3587

When William Parsons, the 3rd Earl of Rosse sketched this nebula in 1848, he thought he saw the face of an owl within the deep-sky object, and it has been known as the Owl Nebula among both amateurs and professional astronomers ever since. In terms of its structure, the nebula consists of three nested shells of ejected matter, with the owl-like appearance deriving from the innermost shell that is not concentric relative to the outer shells. In fact, this shell is more akin to a barrel inclined to our line of sight by about 45 degrees, with the two ends representing the owl’s eyes.

The 8,000-year old Owl Nebula consists primarily of hydrogen, helium, nitrogen, oxygen, and sulphur, that collectively, weigh about 13 percent more than the Sun at an average density of fewer than 100 particles per cubic centimetre. The central star is white dwarf with about 60% of the Sun’s mass, and an effective temperature of 123,000K that makes it shine between 41 and 148 times as brightly as the Sun. The nebula is now expanding at the rate of between 27 and 39 km/sec.

Southern Owl Nebula

Image Credit: ESO

-Nebula type: Planetary nebula
-Constellation: Hydra
-Coordinates: RA 11h 26m 43.78s|Dec. -34° 22′ 11.4″
-Distance: 3,500 light years
-Diameter: 4 light years
-Magnitude: 17.4
-Other designations: PLN 283+25.1, ESO 378-1

The Southern Owl Nebula bears a passing resemblance to the Owl Nebula described above. It does, however, have a diameter of four light years, making it more than twice the size of its Northern Hemisphere counterpart described above. This mysterious bubble of glowing gas looks like it could be the ghost of a star, which in a way is what this planetary nebula is, as the dying star ejects its gaseous outer layers of gas into space. It received its name as its appearance in 10-inch and larger telescopes reveals two dark patches resembling the eyes of an owl.

Duck Nebula

Image Credit: Rogelio Bernal Andreo, Ray Gralak

-Nebula type: Emission nebula
-Constellation: Canis Major
-Coordinates: RA 07h 18m 30s|Dec. -13° 13.8′
-Distance: 11 960 light years
-True Diameter: 30 light years
-Other designations: Thor’s Helmet, GUM 4, LBN 227.66-00.09, SH 2-298, GRS 227.80 -00.20, LBN 1041, RCW 5

While some observers see the wings and grossly misshaped body of a flying duck in this nebula, others see the winged helmet of Thor, a Norse god, hence the ambiguity in the popular names of this 30-light year diameter planetary nebula.

The most remarkable aspect of this nebula is the amount of matter it holds, compared to most other planetary nebulae. All told, the nebula contains several hundred solar masses of ionized material, and an additional several thousand solar masses of neutral, un-ionized matter. While most of the neutral material appears to be interstellar matter swept up by the central star, this material does show some evidence of enrichment through nuclear fusion processes, which makes the exact origin of it somewhat unclear.

The large difference in age estimates is the result of the fact that different parts of the nebula expand at different rates, which range from about 10 km/sec to at least 30 km/sec.

Running Chicken Nebula

Image Credit: ESO

-Nebula type: Emission nebula
-Constellation: Centaurus
-Coordinates: RA 11h 36m 36.0s|Dec. -63° 02′ 00″
-Distance: 6,500 light years
-True Diameter: 120 light years
-Magnitude: 4.5
-Other designations: IC 2944

Some people can see the shape of a chicken running towards the observer in the arrangement of the gas and dust just to the left of centre in this image. Running chicken shaped or otherwise, also unclear is whether or not protostars have been found in the Bok globules (isolated, small dark molecular clouds) seen as dark spots in the nebula.

While some sources hold that no stars have been found in any of the globules (which were named after their discoverer, South African astronomer David Thackeray), images obtained by the 2MASS survey clearly show six stars in the largest globule. However, it should be borne in mind that since some astronomical sources are outdated and can remain so for many years, it is likely that the 2MASS survey had indeed found some stars in one or more of the dark globules shown here.

Cygnus Loop

Image Credit: NASA Ultraviolet view

-Nebula type: Supernova remnant
-Constellation: Cygnus
-Coordinates: RA 20h 45m 58.1s| Dec. +30° 35′ 43” (Note that while these coordinates refer to the “Western Veil Nebula” component of the larger structure, they are sometimes taken to locate the Cygnus Loop Nebula as a whole.)
-Distance: = 1,800 light years
-Diameter: 90 light years
-Age: 5,000 – 10,000 years
-Other designations: Cirrus Nebula, Veil Nebula, Filamentary Nebula, and many others, some of which refer to components of the larger structure

While William Herschel is credited by some authorities as the first discoverer of certain parts of the Cygnus Loop, it is almost certain that he did not name this enormous collection of knots, filaments, and sheets of gas and dust after a swan. In fact, the origin of the name “Cygnus Loop” is somewhat unclear, and the best thing to do is to think of the structure as a ‘loop of nebulosity in the constellation Cygnus”.

The image above shows an ultraviolet view of the entire supernova remnant, and while much of the structure is visible in optical frequencies, only UV, radio, and x-ray light shows the entire nebula. The Cygnus Loop nebula consists of more than a dozen sub-nebulae, sadly making it far too complex to describe in a list such as this, so readers are encouraged to consult authoritative sources to learn more about this nebula.

Seagull Nebula / Parrot’s Head Nebula

Image Credit: Michael Sidonio

-Nebula type: Star forming region (HII region)
-Constellation: Monoceros
-Coordinates: RA 07h 04m 25s|Dec. -10° 27.3′
-Distance: 3,650 light years
-Diameter: ~ 100 light years
-Other designations: GUM 1, IC 2177, Sh2-292

While this nebula is most commonly known as the Seagull Nebula, since its shape suggests the outstretched wings of a seagull, the curious blob of nebulosity near the top of the frame resembles the head of a parrot. Considering that the dark dust lane that bisects the blob represents a mouth and the bright star marks an eye, it is not difficult to see the body of seagull topped by the head of a parrot.

However, the figure of a hybrid bird disappears in the vast scale of the overal larger structure, which is over 100 light-years across and has a reddish glow caused by ionized atomic hydrogen.

Emu Nebula

-Nebula type: Complex of dark nebula
-Constellation: Crux to Scorpius
-Coordinates: RA 12h 50m|Dec. -62° 30″ (Note that these coordinates refer to the Coal Sack, a dark nebula in the constellation Crux, which forms the “head” of the Emu
-Distance: 600 light years
-Apparent Diameter: 7 × 5 degrees
-Other designations: C99

Among the many dark nebulae in the Milky Way, the complex of nebulae that forms the shape of an Emu is probably the most prominent, and easiest to recognize. The image to the left shows an area of this part of the Milky Way, while the bottom frame depicts the same area, but with a line drawing of an emu superimposed on it.

The emu is of huge cultural importance to several Australian Aboriginal peoples, since it is believed that nebula represents the head and shoulders of a “law-man”, who is continuously looking down on the tribes to ensure that infractions of traditional laws and customs do not occur. According to Aboriginal folklore, the “law-man”, whose proper name is Utdjungon, can only be prevented from destroying the entire world by hurling down a “fiery star” if all tribe members always observe all traditional laws and customs to the letter.

Peter Christoforou :