Space

Observatory / Course Archives / ASTR 110 Fall 2019 / Arendsen

Orion Nebula

A nebula is generally known as the "birthplace of stars". It is where many stars are created. It is a giant cloud of dust and gas found in parts of space. Discovered by Frenchmen Nicolas-Claude Fabri de Peiresc in 1610, The Orion Nebula is one of the few that we can see with a naked eye from Earth, it is found just south of Orion's Belt, and in the area of the Orion Constellation. It is one of the brightest nebulas that we know of. The Orion Nebula is about 1,344 light years away from Earth, which is also the closest place of star formations that has been discovered to date, and it is roughly 24 light years across. The Orion Nebula is arguably the most popular Nebula, and we have gained a lot of star formation information from the giant area of gas and dust.

Like referred to earlier, most nebulas are known as "birthplace of stars", or, "star nursery". The Orion Nebula is no different. Because it is the closest of the known nebulas, we have been able to observe roughly 700 stars in different stages. For example, in 1991, something referred to as a "jet" was found in Orion's Nebula. A jet is an energetic outflow, that usually refers to the birth of a young star. We can learn that Orion is still forming new stars, and filling itself with younger stars. Recently, more objects were found in the nebula, known as "Brown Dwarfs". Brown Dwarfs are bigger than planets, however they do not give off any light like a star should.

(Image by Josep M. Drudis and Don Goldman)

Milky Way Galaxy

A galaxy is a giant area in space, filled with interstellar matter and star systems. They come in three categories, spiral, elliptical, and irregular. The Milky Way is one of the bigger known spiral galaxies, and it is where we live. There are at least two hundred billion more known stars in the galaxy, although some thing that number may be closer to four hundred billion. It has a mass of between roughly 750 billion solar masses, and 1 billion solar masses, with a diameter of about one hundred thousand light years.

In this image, you see the Milky Way Galaxy going vertical next to the rock formation, found somewhere near the Persian Gulf. Interestingly, inside of the rock next to the Milky Way, you see a bright spot. That bright spot is the gas giant, Jupiter. Our solar system is located in the disk of the Milky Way, and within the outer regions of the galaxy. When you look at this photo or any photo of our galaxy, you are looking at many different things. One thing you are looking at is young stars being formed in the disk of the spiral galaxy. Since the stars are forming very slowly, you may not realize it at the time what you are seeing. On the other hand, another things you are looking at, is older stars, mostly found in the bulge of a spiral galaxy.

(Image by Mohammad S. Hayati)

Planet Neptune

Neptune is the outermost planet found in our solar system, Pluto not withstanding. An orbital year for Neptune is 165 years on Earth, even though it rotates in just 16 hours, in spite of the much larger volume. While it is the smallest of the gas giants, it is a giant nonethelss. It is more than 17 times the weight of Earth, and over 57 times larger. This is an amazing picture of Neptune, taken by Voyager 2. However not seen in this photo, Neptune has 6 known rings, and 14 known moons orbiting the ice giant, as it is also referred to. The planet was first "discovered" by scientist Galileo Galilei, however he only thought it was a star. The star was truly discoverd later using hypothesis', only because astronomers Urbain Le Verrier and Johann Galle noticed that Uranus' orbit was being affected in a way that did not match their model.

In this picture, you get a very close-up look at Neptune and its features. Notably, Neptune is very visibly made up of the color blue. There is a big reason for this. Mainly, the reason is that Neptune is made up of gases like Hydrogen and Helium. In addition, it is also made up of Methane. Methane is very important to how we see Neptune, because Methane absorbs the red light from the sun, and leaves Neptune to appear blue. Scientists also conclude that there is an unknown reason that Neptune appears blue. Along with Uranus, Neptune is known as an Ice Giant in addition to being known as a Gas Giant. An Ice Giant typically has more Ice in their core, in comparison to the other gas giants.

(Image by NASA, taken by Voyager 2)