The Crab Nebula

I have a really hard time coming up with blog ideas, mainly because I'm not used to blogging or any of that sort of thing (I don't have a personal blog or a Facebook page or anything like that). However, thinking back to a somewhat recent game of Astronomy Monopoly gave me the idea for this blog. While playing, I became intent on "owning" (a phrase I hate when it comes to astronomical bodies) the crab nebula. But aside from it being in a lucrative position on the game board, what makes it so interesting?

The Crab Nebula is a leftover from a supernova. The brilliant colours that are observed (well, from colourized pictures) are all from the gas that was once a part of the star, lit up by x-rays and other forms of electromagnetic radiation.

How is this not awesome?

In relation to my last blog, the Crab Nebula is the result of a star going supernova, which created a neutron star. When the light from the supernova finally reached Earth, it was so remarkable that it was widely recorded across many civilizations and remained bright for months, giving the Sun some massive competition for being our only appreciable source of light from the sky. The original star was about 9 times the mass of our sun but now what is left of the source star is tiny and its remains are strewn all around it. The gas surrounding the neutron star weighs about 5 times that of our sun! The central ring of gas is comprised mostly of helium, and more outwardly comprised of heavier elements.  Also, the neutron star pulses very quickly, though like all neutron stars it is slowly losing its energy and is slowing down. 

The Crab Nebula is what is known as a "diffuse nebula", meaning its boundaries are not clearly defined and it is very bright in the infrared. When viewed in the infrared, the nebula appears as a very intense blue colour. It has also been suggested that the blue of the Crab Nebula is due to electrons curving due to their high velocities. This is due to the inherently strong magnetic field within a pulsar, causing the electrons temporarily caught within it to be sped up.

Additionally, the Crab Nebula is still expanding, which helps us determine how far away from us it is. That being said, it is about 2 kiloparsecs away (or about 6.17*10^19 meters), so while not the closest thing, it is still closer to us than the center of our own galaxy.

The Crab Nebula is still a subject of great interest, even today. There is still a lot that we don't know concerning the neutron star at its center because it is very difficult to see past the gas surrounding it. For instance, we don't know how much the neutron star weighs, its radius, luminosity, etc. We do know it is a young neutron star and its pulse rate (33 milliseconds) and the nebula itself is the source of very strong x and gamma rays. The mass of the neutron star is still quite a mystery since scientists are currently unable to resolve the predicted star mass (pre-supernova) to the remnants existing today. Additionally, the nebula is almost directly in line with the Earth, meaning it often gets covered up by things between us and it, including the plasma from the Sun. Also, its aforementioned expansion seems to be increasing, making it difficult to date exactly when the supernova originally happened.

"Crabby McAwesome" (by far the most professional nickname I've given to anything) is an historic nebula that we still have much to learn about and hopefully as our technology improves even more, we will find new ways to gather information about it, giving us more insight into how this badass nebula works and possibly what the star was like before it exploded.