Nebulae of all types are among the most spectacular-looking structures in the entire Universe, and have been an endless source of intrigue and discovery for astronomers. How we perceive them, however, is often thanks to the skill of astrophotographers and imaging experts, rather than our own observing skills. In fact, many nebulae are invisible to our eyes, and we only become aware of their existence after colors are assigned to different wavelengths or emissions in astronomical images.
With that in mind, we present a selection of nebulae of various types that are said to resemble aquatic animals to varying degrees. In some cases, the resemblance is clear, while in others a certain amount of imagination is required to make the connection. Nonetheless, whatever you see in these nebulae is less important than seeing them for what they are, namely proof of the everlasting process of star birth, star death, and the continuous, churning, evolutionary processes that shape the Universe. Let us start our tour of the cosmic oceanic depths.
Lobster Nebula
- Nebula type: Emission nebula and star-forming region
- Constellation: Scorpius
- Coordinates: RA 17h 25m | Dec. −34° 19′
- Distance: About 8,000 light-years
- Other designations: NGC 6357, War and Peace Nebula
The appearance of a lobster in this nebula is quite striking, with some observers likening the spindly pillars of gas and dust to a rock lobster. The enormous complex of glowing gas and dark dust is seen here in infrared light, which allows ESO’s VISTA telescope to peer through some of the obscuring material and reveal many of the stars embedded within it.
NGC 6357 is also known as the War and Peace Nebula. Whatever this nebula resembles, the fact is that it is a huge star-forming region that contains many newborn stars that are blowing bubbles and cavities into the surrounding material, thus creating the ragged, wind-blown scene seen here.
The nebula also contains an open star cluster, designated Pismis 24, which was once thought to contain a monster star of roughly 300 solar masses designated Pismis 24-1. Higher-resolution observations subsequently resolved Pismis 24-1 into multiple components, reducing the estimated mass of each individual star considerably.
Prawn Nebula
- Nebula type: Emission nebula and H II region
- Constellation: Scorpius
- Coordinates: RA 16h 57m | Dec. −40° 20′
- Distance: About 6,000 light-years
- Diameter: About 250 light-years
- Other designation: IC 4628
If one looks closely, the bright ridge of glowing gas might just resemble a prawn, albeit a prawn without legs or a tail.
In fact, the whole nebula shown here is an enormous star-forming region that contains clumps of hot, young stars. Their intense ultraviolet radiation ionizes the surrounding hydrogen gas and causes the clouds to glow. This exceptionally detailed image was taken with the VLT Survey Telescope at ESO’s Paranal Observatory in Chile.
Crab Nebula
- Nebula type: Supernova remnant
- Constellation: Taurus
- Coordinates: RA 05h 34m 32s | Dec. +22° 00′ 52″
- Distance: About 6,500 light-years
- Diameter: About 11 light-years
- Magnitude: 8.4
- Age: About 970 years
- Other designations: Messier 1, M1, NGC 1952, Taurus A, Sh2-244
The Crab Nebula needs no introduction, but what may not be commonly known is that its name derives from a drawing made by the 3rd Earl of Rosse, whose sketch of the object reminded him of a crab.
The nebula is the expanding remnant of a supernova observed in 1054. Its tangled filaments consist of material expelled by the exploded star, while the bluish glow in its interior is powered by a rapidly rotating neutron star, or pulsar. Electrons accelerated to enormous speeds around the pulsar’s magnetic field produce this inner glow through synchrotron radiation.
Stingray Nebula
- Nebula type: Planetary nebula
- Constellation: Ara
- Coordinates: RA 17h 16m 21.1s | Dec. −59° 29′ 24″
- Distance: About 18,000 light-years
- Diameter: About 0.08 light-year
- Magnitude: 10.75
- Other designations: Hen 3-1357, PN G331.3−12.1
When one discounts the absence of a “tail,” this tiny planetary nebula might just bear a passing resemblance to a stingray coasting through the interstellar void.
The Stingray Nebula is particularly remarkable because astronomers have been able to observe dramatic changes in it over only a few decades. The gas surrounding its central star became ionized late in the 20th century, briefly producing what was described as the youngest known planetary nebula.
Subsequent Hubble observations revealed that the nebula then began fading surprisingly quickly as the central star cooled. The Stingray therefore provides astronomers with an unusually rare opportunity to watch the evolution of a planetary nebula on a human timescale.
Manatee Nebula
- Nebula type: Supernova remnant
- Constellation: Aquila
- Coordinates: RA 19h 11m 49s | Dec. +04° 59′ 12″
- Distance: About 18,000 light-years
- Age: About 20,000 years
- Other designations: W50, SNR G039.7−02.0
Its shape is probably closer to that of the animal it is named after than almost any other nebula. In this image combining radio and infrared observations, the mass of gas seems to mimic a manatee at rest, drifting on its back with its flippers crossed across its chest.
At the heart of the Manatee Nebula is the remarkable microquasar SS 433. Powerful jets from this binary system interact with the surrounding supernova remnant and have helped stretch W50 into its unusual elongated shape. The radio-emitting remnant is shown together with infrared background emission in this composite view.
Turtle Nebula
- Nebula type: Planetary nebula
- Constellation: Hercules
- Coordinates: RA 16h 44m 29.5s | Dec. +23° 47′ 60″
- Distance: About 6,500 light-years
- Other designation: NGC 6210
While some observers report seeing the shape of a tortoise’s shell in this nebula, its complex appearance is also a striking illustration of the way a dying star can shed its outer layers.
The Hubble image reveals several distinct shells and structures surrounding the hot central star. Rather than expanding as a simple spherical cloud, the ejected material has developed an irregular, layered appearance as successive episodes of mass loss interact with one another and with the surrounding environment.