You Spin My Star Right Round

I was so excited about the weekend that I just went ahead and decided to have it early! That’s the joy of a flexible schedule. I took all of Friday off and enjoyed it immensely. Of course, the work still had to be done. That’s the joy of being a stubborn goal-setter, I suppose. But I did a bit on Saturday and a bit today and still enjoyed the rest of my weekend.

Yesterday I tackled a Mathematical Methods chapter on line, surface, and volume integrals. The line integrals are straightforward enough, once I got the hang of proper parametrization and limits again. It got a bit trickier with the surface and line integrals, and I confess that by the end of the chapter I was sort of lost. Most of the examples in this section were proofs rather than working out samples, and I find that doesn’t help me grok the material as well. Divergence and curl manage to be more confusing in integral form, although I know it is quite practical. In any case, it was a solid chapter and had lots of physics applicability (Maxwell’s equations, anyone?).

Today I settled in for a good read in Bob. I finished Part I, so I got to start on Part II, which is all about stars. This chapter dealt with binary stars and how we can use their orbital characteristics to glean information about them. It’s quite an interesting topic and one of the biggest challenges of astrophysics. How can we, stuck on Earth or the immediate vicinity, gather meaningful data about things that are farther away than we could ever hope to directly observe? Luckily, smart people have come up with lots of methods over the years. This chapter briefly covered several of them, including light curves, spectrum shifts, and astrometric wobbles. It also gets into the angle of inclination and how we deal with the fact that, by sheer chance, we have to observe other systems from whatever angle we have, which may not be nicely head-on or side-on. Lastly, the discussion moved to extrasolar planets, which can be detected by many of the same methods, although their effects are much, much smaller because planets are a lot smaller and dimmer than stars! I had another chuckle about the ageing of this text. At the end of the chapter, it states, “Although Earth-sized planets have yet to be discovered around solar-type stars, […] it seems likely that such discoveries will occur soon.” Exoplanets as a field has been experiencing huge growth, and they were not wrong!

Go go exoplanets!

Photo: NASA Ames/JPL-CalTech/R. Hurt