All About Nebulae Trivia Quiz

Answer: Gas clouds

A nebula is a gas formation in space, primarily made up of hydrogen and helium and the lighter elements. The interesting thing about these gas clouds is that the density of nebulae is actually less dense than the emptiest vacuum that can be created on Earth. Since nebulae can stretch out for really large areas, light years even, they create their own gravitational field and the gases have the potential to clump together to start creating other things.

In the picture are the 'Pillars of Creation', a formation in the Eagle nebula.

Answer: Orion Nebula

The French astronomer Nicolas-Claude Fabri de Peiresc, also known as Peirescius, was believed to be the first to record seeing this nebula for what it is. In 1610 he wrote that he had observed the nebula as a "small illuminated cloud" within the sword of Orion. In the constellation, it is the central object in the sword part of the sky-picture. Orion has a magnitude of +4.0 meaning that it is visible to the naked eye, unlike the vast majority of true nebulae.

In the picture is the Orion nebula.

Answer: Star formation

The H II region nebulae are clouds of hydrogen atoms that have been stripped of their electrons causing the atoms to become ionized... basically, it's a cloud of protons floating in space. Some of this gas originally condensed in the center to form small stars and these new stars usually emit ultraviolet rays that ionize the hydrogen. These stars also create a shock wave of energy driving the gas outward, and, over a 'short' period of time (about a million years), most of the hydrogen gas gets blown away.

Pictured is NGC 604, an H II region within the Triangulum galaxy. About 200 new stars can be seen forming here.

Answer: False

In the year 1054 a 'visitor star' was observed to be so bright that it could be seen during the day as well. It stayed for a couple of months before getting more dim. While the remnant cloud, the Crab Nebula, was observed many times in the 18th and 19th centuries, it was not until 1928 when Edwin Hubble suggested that this cloud was associated with the supernova event that occurred in 1054 did everything fall into place. Today, there have been more nebulae that have been associated with supernova events, though none that have been observed on Earth, yet. The light from a supernova event that occurred six thousand years ago is expected to reach the Earth in about a thousand years. Get ready...

You can see a supernova remnant IC443 in the picture, also known as the Jellyfish Nebula.

Answer: Dark nebulae

Dark nebulae are gas clouds so dense that they absorb all wavelengths that are emitted from their centers. They can be seen by comparing the 'darkness' to its background and mapping the cloud that way. They have never been observed as having a regular shape. The majority of dark nebulae are elongated in shape. These hide inside them new stars as well as astrophysical masers. The presence of dust in these clouds may indicate that they are ancient star remnants, but there are also hydrogen, helium, carbon dioxide, ammonium and other gasses present.

In the picture you can observe the Coalsack Nebula near the star Acrux. This is located in the constellation of Crux, or, the Southern Cross. The dark nebula can be 'seen' as the dark cloud in the center of the image.

Answer: They reflect the light of the nearby star

Reflection nebulae are clouds of dust that are close to a star but the star does not have enough energy to ionize the nebula. However, the light from the star is able to be reflected by these nebula, hence their name. These nebulae consist of dust particles made from carbon (literally, diamond dust floating in empty space) as well as heavier metallic elements such as nickel and iron. These nebulae were first noticed as they have an identical, though weaker, emission spectrum as the star located very near to them.

In the picture is the Witch Head Nebula, also known as IC 2118. This cloud of dust is associated with the star Rigel, located in the constellation of Orion. As you can see, Rigel's blue light can be seen in the nebula cloud shaped like a face of a witch.

Answer: Planetary nebulae

When they were first observed, these nebulae were said to resemble planets, hence they were given the name 'planetary nebulae'. Once the picture became clearer as to what they were, the theory changed but the name stuck. Today we know that planetary nebulae are gasses and particles that are given off by a red giant star at the end of its life. These particles are then ionized by the star at the center of the system giving the nebula an interesting look when seen from Earth. The red giant will eventually collapse into a white dwarf and then expel all the remaining material out into space. This allows heavier elements to disperse throughout the galaxy.

The picture shows the Cat's Eye Nebula. It is seen here in visible light as well as X-ray light giving it a very interesting look.

Answer: They collide with other clouds of material at great speeds

Proto-stars, or newly formed stars, get most of their material from space and collapse to start fusion reactions and enter the main sequence of stars. However, these stars are usually spinning way too fast to be stable and need a mechanism in order to slow themselves down. They create jets from their polar regions and spew them out along the axis of rotation. These jets travel at great speeds - hundreds of kilometers per second! If they encounter other clouds of material, the collisions cause the Herbig-Haro objects to ionize, maybe even just partially, and emit light. These nebulae are very short-lived and last a mere thousand years or so.

Pictured is HH24, a Herbig-Haro object. If you zoom in, you can see the jet of ionized light colliding with a cloud of gas creating an ionized mess.

Answer: The outer layer of the star

When a star begins to near the end of its life, it begins to cool down because its hydrogen starts running out. When this happens, the fusion reactions in the core start to slow, less hydrogen is turned to helium, the core cools, and there is less core pressure to keep the star at its former size. When this happens, the outer shell of the star does not get sucked back into the star. It gets ejected into space in two bipolar high-speed jets and these reflect back the infrared radiation from the star. These can be seen by telescopes and are identified as protoplanetary nebulae, or sometimes, pre-planetary nebulae. They do not last more than ten thousand years and, at some point, they form the planetary nebulae which do emit their own light.

In the picture is a protoplanetary nebula called IRAS 20068+4051 found in the constellation of Cygnus.

Answer: Black hole

One side of X-1 is a normal star, the other is a very compact star that is five times more massive than our sun. This is the black hole, because even if it was a neutron star - the most massive object possible - its gravity would force a collapse of the system. This black hole is feeding off of the companion star at a rate of a quarter of Earth's mass every year. Surrounding this system is an ionized nebula consisting of He III, so, helium atoms stripped of all of their electrons. This nebula emits some light, but, it primarily reflects the massive X-ray emissions given off by the black hole.

In the picture is the system of LMC X-1, in X-ray light.