Nebulae: Do You See What They See? Quiz

Answer: Horsehead Nebula

The interstellar clouds referred to as nebulae (plural of "nebula") are made up of dust, hydrogen, helium, and other ionized gases. The darkness of the Horsehead Nebula is the result of the light of stars blocked from our vision by the dust. The Horsehead Nebula, also known as Barnard 33, can be seen when looking into the belt region of the constellation Orion.

It is about 1500 light years from Earth. It was first recorded in 1888 by Williamina Fleming from Scotland. Fleming also helped establish a system for recording stars, and she helped catalog a great number of stars as well as other astronomical bodies and events.

Answer: Butterfly Nebula

The existence of the Butterfly Nebula has been known about since at least 1888. As noted in the question, it is a bipolar planetary nebula. Some nebulae form as planetary nebulae, meaning that as low-mass stars (such as the earth's sun) enter their final stages, they shed their outer layers into their atmospheres. As a result, the temperature of these stars rises and ultraviolet radiation ionizes the outer layers that have been shed. The "bipolar" term simply refers to the fact that the nebula appears to have two symmetrical lobes arranged opposite each other. The nebula NGC 6302, seen here, can be observed when looking toward the constellation Scorpius.

The white dwarf star at the center of this nebula is estimated to be over 200,000 degrees Kelvin (K) and is one of the hottest known stars in our Milky Way galaxy. The lane in the middle of the nebula appears to contain crystalline silicates, crystalline water ice, and quartz, and some speculate that there may even be carbonate material there, though this is hotly contested.

Answer: The Red Spider Nebula

The white dwarf star at the center of the Red Spider Nebula could have a surface temperature of anywhere from 150,000 to 500,000 K. It is one of the hottest white dwarves known, and its powerful winds, which reach speeds of 300 kilometers per second, have created waves 100,000,000,000 kilometers high.

While nebulae appear to be very small clouds to us as we look through our telescopes, they are really incredibly large, many of them being hundreds of light years in diameter. The Red Spider Nebula, also referred to as NGC 6537, is another example of a planetary nebula.

Answer: Mystic Mountain

Most nebulae are the result of gravitational collapse within an interstellar medium. As the supreme weight of gases and other materials causes the conglomeration to collapse upon itself, stars begin to form in the center, and their ultraviolet radiation causes the cloud to glow due to ionization. Newly born stars within Mystic Mountain's peak, which is about three light years in height, propel gases from the peak and create the dazzling display of colors seen in the picture.

The Carina Nebula is also referred to as NGC 3372 or the Grand Nebula.

The Carina Nebula's name comes from its appearing in the Carina constellation as seen from Earth.

Answer: Spirograph Nebula

The Spirograph Nebula, or IC 418, is located in our home galaxy, the Milky Way, and existed as a red giant star only a few million years ago. As the star exhausted its nuclear fuel, the outer regions began expanding, creating the intricate display seen in the picture and leaving behind an extremely hot core that will eventually become a white dwarf.

The visible pattern is similar to the geometric shapes created with the Spirograph toy first created by British engineer Denys Fisher in 1965. However, mathematician Bruno Abakanowicz invented the spirograph during the late 1800s to assist with the calculation of geometric curves, and some form of the toy existed as early as 1908 when the Sears catalog advertised the Marvelous Wondergraph.

Answer: Hourglass Nebula

Situated 8,000 light years away from Earth and visible when looking at the southern constellation Musca is the young planetary nebula MyCn 18. The shape of the Hourglass Nebula, or the Engraved Hourglass Nebula, is most likely the result of a rapid expansion of a stellar wind within a much more slowly expanding cloud. This cloud is denser near its equator than its poles, thus creating the "eye" effect.

Overall, nebulae have very little density. While they are certainly more dense than the empty space surrounding them, they have less density than a vacuum created here on Earth. In fact, the mass of a nebula the size of the planet earth would be only a few kilograms.

Answer: Pillars of Creation

The Pillars of Creation is part of a region of gas that contains the Eagle Nebula and is around 7,000 light years from Earth. While the dust and molecular hydrogen gas within the "pillars" are in the process of forming new stars, interestingly, these materials are also being eroded by the ultraviolet light from newly-formed stars near the pillars. This process of erosion is called photoevaporation. The "pillars" are amazingly larger than our own solar system, and the left-most "pillar" is itself four light years long.

Some scientists speculate that ironically the Pillars of Creation may already be "dead" or destroyed and that we are seeing an image created by light that is only just now reaching our Earth. Scientists recently found a cloud of hot dust nearby the Pillars of Creation that they believe is evidence of a supernova, which would have destroyed the image of the Pillars of Creation around 6,000 years ago. In another 1,000 years we will probably finally see the destruction of these clouds.

The image seen here was first captured on 1 April 1995 by two Arizona State University students.

Answer: Crab Nebula

Some nebulae are created by supernovas, which are stellar explosions that for several Earth weeks or months outshine the entire galaxy in which they are found. The materials expelled as the result of the death of a star become ionized, creating spectacular light shows. The Crab Nebula, or NGC 1952, is a remnant of a supernova. This nebula is also known as a pulsar wind nebula, which contains a highly magnetic rotating neutron star at its center. Neutron stars are the smallest and densest stars known in the universe. While most are only about fourteen miles in diameter, they have a mass twice that of the earth's sun. They also rotate incredibly fast, and this rapid motion creates the effect of a pulse of light. The neutron star at the center of the Crab Nebula is about seventeen to nineteen miles across and rotates 30.2 times per second.

The Crab Nebula's name is the result of a drawing made by William Parsons, who observed the nebula through a telescope in 1840.

Answer: The Eagle Nebula

The Eagle Nebula is amazingly about 90 trillion kilometers high and is part of an H II region, which is a large low-density cloud of partially ionized gas in which stars have formed. This particular H II region is made up mostly of an open cluster of stars found in the direction of the constellation Serpens. An open star cluster is a collection of a great number of stars formed from the same giant molecular cloud and bound by gravitational forces.

This particular cluster has approximately 460 stars, and the cluster's luminosity is so tremendous that it is one million times brighter than our solar system's sun.

Answer: Ring Nebula

Astronomer Antoine Darquier de Pellepoix discovered the Ring Nebula in 1779 but was not quite sure what he was seeing at that time. The nucleus of this nebula consists of oxygen and carbon, and perhaps a planet like Earth might exist there or will at some time.

The ionization of this oxygen is responsible for the blue in the center while the red outer shell is the result of ionized hydrogen. The Ring Nebula is growing rapidly; it currently expands one arcsecond every Earth century.