A Stellar Talk

I felt a lot better today, just in general. Maybe it's that I've finally settled into a comfortable sleep schedule, maybe it's that I wasn't assigned too much homework yesterday, and maybe it's that I'm feeling more comfortable with both my classmates and the concepts taught. Whatever it was, I woke up slightly more enthusiastically than the usual. I showered, brushed my teeth, and went down to breakfast to sit with the late-eating portion of my Physics of Stars class. 

Class began with more discussion of stellar evolution, with the Sun as the main example, as it is the easiest star to observe. Stars go through a few different stages of life. The longest and most important one is the period of billions, or sometimes millions of years during which a star "peacefully" (as the book put it) fuses hydrogen atoms into helium atoms to maintain equilibrium. Equilibrium is reached in a star when the pressure created by the heat of the nuclear fusion pushing outward equals the pressure inwards caused by gravity. After this, stars gradually expand as more and more of the hydrogen outside the core is fused (due to the increased surface area) and turn into giants. We have not covered what happens after this, but I believe the possibilities are becoming a neutron star, a supernova, or a white dwarf. 

After discussing the stars' actual lifetimes, we looked at HR diagrams, or graphs of the temperature of a star versus the luminosity of a star. By putting several stars on this diagram, we can see how different classes of stars (differentiated by surface temperature ranges) evolve from the trends on the graph. We put this new knowledge into effect by separating stars into these classes based on the peak wavelength of their blackbody spectrum. Gourav also used this activity to make a good point about trying too hard to find something, as three of the "stars" that we classified were, in actuality, galaxies!

After this activity, we broke early for lunch. The main points of discussion were the mysterious time at which linens could be traded in for fresh clothing and the limited-admission group going to The Color Purple, a musical. I sadly did not get in, but I think that I will show up anyway to see if anybody drops it.

For the second half of class, a guest speaker named Brian Nord came in to talk about the historyof artificial intelligence, how it works, and how it can be used to analyze images of celestial objects. What it can do is find only the images from a large data set that look alike after being given several examples of the desired result.

The last 45 or so minutes of class was free project work time. Mr. Kron thought that the initial project idea, which included doing our own observations, would be better suited to our time at Yerkes Observatory. Instead, we are going to observe the gravitational deflection of starlight passing near the Sun. The mass and gravity of the Sun create a "dip" in the plane of space-time, causing light to be slightly bent from its original path. This can be measured as a change in the apparent location of the star in the sky when it is and is not adjacent to the Sun.

The rest of the day was a mix of discussing others' and mine own classwork/textbooks, studying, and writing this blog

Good night!