My First Hitchhike Journey into the Universe with Astrophysics Student Pass [Part 2]
Halló, velkominn. This is the second part of the journey––in case you missed the first part. Be prepared captain, this one will be a bit technical!
My second year in astronomy was a bit easier than the 1st year training––in which many of the students disagreed with this statement. Joined the literary club (Ali was the spearhead) and it expanded into a wider underground network. Then I met Fabu, the guy from biology, which at the time considered a nerd, but in fact, he has a great mind and courage.
Observation becoming one of the main topics, in which techniques for operational and measurement purposes play a critical role. The other one is the physical area of astrophysics (u do not say).
I am not a big fan of scale-converting, it is much better to spend time cooking for two or looking for memes. Here is a hint: everything is in degree, minute, and second. All you have to do is to remember the type of coordinate system conversion. Alt azimuth, an easy one–look around and upfront. Equatorial is the most used, the extended version of earth equator and polar, with a little real hands-on telescope handling practice, you can master it, but much harder if you only imagine.
This discussion is underrated, but the north celestial pole is going precessed. Polaris was not the north star a long time ago.
The galactic coordinate is not covered yet, but it is the most interesting. Pretend that human is by no means the center of the universe, and we do not know what weirdo lies there. Here is the trailhead of the black forest. Many people get lost, never turned their eyes and mind back, but I will be your friend to the very end. I assume now you become my company here, congrats. The starting point is already inside the forest and there is no entrance gate. There is a map as seen below, but not so accurate since it was based on connected dots from prior observations, which were made by other lost fellows.
The things that should be checklisted:
- Galactic center coordinate (RA = 17h 45.6m, Dec = -28" 56')
- Galactic north pole (RA = 12h 51.4m, Dec= +27" 07')
- Galactic inclination to the earth equator (63 degree).
So we can imagine that the solar system, which is called the ecliptic, is inclined to the galactic disk, and the earth is inclined around 23 degree to the solar ecliptic. Thus, the ecliptic is 40 degree inclined. And here is a meme I found at 9GAG about how the action of earth evolution is, and from an article by Ethan Siegel, it is not something vortex-like as seen below.
The general relativity took place at large scales, and it is far more complex. There is a finding that Milky Way pulled towards Andromeda within the local group, which was pulled by the galactic group in Laniakea supercluster.
Thankfully (or not, maybe), there is an underdense region 300 light-years across our solar system known as the local bubble. This object left my mind in limbo at the Interstellar Matter examination as I was clueless at the time.
The local bubble is constrained by massive stars and supernova remnants that disrupt dense interstellar matter and drive the underdense region into the void(Frisch, 2007). The region was discovered by Fitzgerald in 1968, traced by excess color measurement which implies to be less populated with interstellar matter.
The lower mean extinction refers to a lower density of interstellar matter. This area was created by a blast wave from the star formation process during the past 25–60 million years near our solar system. The surrounding local bubble is covered by hydrogen and CO molecular clouds which vary in density.
