Nebula (plural, “nebulae”) is a Latin word meaning “cloud;” these majestic and graceful objects are indeed cloud-like. Nebulae are composed of interstellar ice, hydrogen, helium, and other gasses, instead of being packed with water vapour like clouds on Earth.
Interesting Facts about Nebula
They don’t seem to have much mass, like a cloud on Earth. If weighed in kilograms, one as large as earth will weigh just about as much as a cat. Let us uncover some interesting facts about Nebula.
1. Formation
Nebulae are usually formed in the interstellar medium by a gravitational collapse of gasses. The falling particles have their own gravitational pull and clump together to form these clouds.
2. Ginormous
The most nebula is massive and covers light-years – even millions of light-years. Nebulae occupy, on average, trillions and trillions of miles of space. For reference, the circumference of the Earth is just under 8,000 miles and the circumference of the Sun is around 865,000 miles. Even a small nebula would consume our entire solar system with ease-they are vast regions.
3. Star Nurseries
Nebulae are also referred to as universe star nurseries since stars also form within the nebulae. According to scientists, under their own gravitational force, gas and dust inside such nebulae clash together. As a result, clouds tend to compress and become more compact. The denser they are, the hotter they get. These finally become so hot that it ignites the hydrogen present in them, and new stars come to life.
4. Looks
We know it’s ginormous but how do they look? Nebulae have shapes in myriads. Others look like the head of a horse, others look like a crab, some look like a butterfly and some look like the eye of a cat!
5. Dark Nebula
Dark nebula of carbon, silicon, and a number of other elements appear dark because they are so thick that they block the stars’ light in the background. Such small particles are covered in frozen nitrogen and carbon monoxide, which absorbs visible light and thus cannot be seen with a regular telescope. Rather, they can only be seen in the infrared spectrum as mysterious forms. While these nebulae do not emit any light, they can still become Stellar Nurseries and construct planets and other large astronomical bodies. There is a dim spot thought to be a Dark Nebula in the middle of the Milky way Cygnus constellation. Some examples of Dark Nebulae are the Coal Sack Nebula and The Great Rift.
6. Emission Nebula
As a star forms inside a nebula, ultraviolet rays are released and the whole nebula is illuminated, resulting in what is known as the emission nebula. Due to the rays of the sizzling hot particle, the emission nebulae are typically pink or red in colour but may have other colours.
7. Planetary Nebula
A planetary nebula is a kind of emission nebula, meaning it is made up of ionized gasses that emit light instead of absorbing it. Planetary Nebulae appear greenish and round (like a planet) through a telescope and develop as other stars grow past their life cycle’s Red Giant period.
They shed their outer layers of the atmosphere at this point leaving just their core. These remains are known as White Dwarfs. The White Dwarf begins to emit light, and the remaining dust and gas turn into a Planetary Nebula. They not only look like planets but even circle their stars in the same way as planets do. Types include the Ring Nebula, a vivid hot spring pool that resembles those found in Yellowstone National Park.
8. Bipolar
Many planetary nebulae have what is named a bipolar structure. Such nebulae appear as hourglasses, often with each end of the “hourglass” spreading from the middle long and thin in either direction. These are often wide-spaced like butterfly wings. While listed among them, astronomers are not quite sure whether or not they are connected to planetary nebula.
9. Reflection Nebulae
Unlike Emission Nebulae, Reflection Nebulae reflects only the light of surrounding stars and nebulae. Such nebulae, like the sky, often appear blue and for quite the same reason. The dust in such clouds scatters only light at the blue end of the spectrum in the wavelengths.
The Witch Head Nebula in the Eridanus constellation, which is 900 light-years away, is an example of both a Reflection Nebula and a Supernova Remnant. A Supernova Remnant happens when one of the strongest events in the universe, a supernova, sends matter in every direction for hundreds of light-years. The extremely beautiful Crab Nebula in the constellation of Taurus is another example of a Supernova Remnant.
10. Supernova Remnant
A Supernova Remnant happens when one of the strongest events in the universe, a supernova, sends matter in every direction for hundreds of light-years. The extremely beautiful Crab Nebula in the constellation of Taurus is another example of a Supernova Remnant.
11. Diffuse Nebula
A diffuse nebula, like very thin clouds in the sky, is one which is stretched out and whose edges are not easy to describe. Diffuse nebulae are typically nebulae of emission, nebulae of reflection, and/or dark nebula. One characteristic they share is that they emit a lot of infrared light from the dust of the nebula, no matter how visible they might be.
12. Pulsar Wind Nebulae
Pulsar wind nebulae, also known as plerions, are found within the shells of supernova remnants. They were also detected among older pulsars, the supernova remnants of which have vanished. These can tell astronomers a lot about how the pulsar of the nebula interacts with the space around it by careful observation of the pulsar wind nebulae, making them a great find for pulsar-interested scientists.
13. Cat’s eye nebula
The Cat’s Eye Nebula is also called NGC 6543 and is a planetary nebula in the Draco constellation. William Herschel first discovered it in 1786, and in 1864 it became the first planetary nebula to be detected with a spectroscope, giving astronomers insight into what makes up the planetary nebulae.
In its structure, the Cat’s Eye Nebula is very complex, possessing knots, loops, bubbles, circles, concentric rings, and a very wide (over three light-years) yet faint halo extending far from its center.
The explanation for their formation has not been well known. Often known by other names, the Eagle Nebula contains Messier 16 / M16, NGC 6611, the Star Queen Nebula, and The Spire. The names “Eagle” and “Star Queen” derive from what astronomers thought a dark region appeared like in the middle of the nebula.
14. Eagle Nebula
Often known by other names, the Eagle Nebula contains Messier 16 / M16, NGC 6611, the Star Queen Nebula, and The Spire. The names “Eagle” and “Star Queen” derive from what astronomers thought a dark region appeared like in the middle of the nebula.
It is part of a diffuse emission nebula, called IC 4703, or H II region. It is located in the Serpens Cauda constellation and the Eagle Nebula is in the Sagittarius Arm of the Milky Way. This nebula became especially popular in pictures due to an image taken by the Hubble Telescope of an area called the Pillars of Creation.
15. Horsehead Nebula
The Horsehead Nebula, also known as Barnard 33, was first identified by Willamina Fleming in 1888 and is a dark nebula in the constellation Orion, just south of the easternmost star in the Belt of Orion. It is part of the Orion Molecular Cloud Cluster and is a large group of nebulae and stars in the constellation.
The Horsehead Nebula is also featured in images, as it appears very well against the surrounding portions of the Orion Complex, being a dark nebula. Like with other nebulae it gets its name from its shape. Especially when viewed with less effective Earth telescopes, it looks like a horse’s head.
16. Boomerang Nebula
The Boomerang Nebula is probably the coolest place to exist in our universe. This is also known as the Bow Tie Nebula. This was first observed in 1980 by two astronomers from Siding Spring Observatory using an Anglo-Australian telescope.
They did not get a good view and found a slight asymmetry in the nebula lobes and then named it the nebula of Boomerang. The Hubble Space Telescope later in 1998 observed the nebula ‘s proper symmetrical form which looks much like an hourglass. The nebula temperature is -272 degrees centigrade which is just 1 degree above absolute zero.
