This week we finally started talking about searching for life outside our own solar system.
Learning Outcomes for Week 11:
By the end of this lesson, students should be able to explain the following to a general audience:
- How stars evolve and how we classify them
- How we detect planets around other stars
- What we have learned about extrasolar planets
- Are Earth-like planets rare?
I started with a quick review of the main concepts of the week 10 content, since we didn’t have a lecture. I also gave some quick stats about the 2nd midterm. I had many students come to my office hours to review their tests, which was a nice change from the 1st test.
We began class by talking about how stars are classified by their spectral types: OBAFGKM. The typical mnemonic device to remember this is Oh Be A Fine Guy/Girl Kiss Me. I think this is kind of out-of-date, and heteronormative, so I asked the students to come up with better solutions, and they took on the challenge. Some favourites are:
- Oh boy, a freaky giraffe kissed me
- Obviously Benevolent Astronomers Find Gilbert’s Kahoots Magical
- Only Brilliant Astronomers Find Gratitude Knowing Mnemonics
- Oil Butter And Fat Gonna Kill Me
- Our Best Actions Favour Good Karma Moments
- Out Back, A Fat Goat Kicked Me
- Oh boy another fun game, kill me
- On birthdays all friends give kind memories
- Only Brilliant Astronomers Find Gross Killing Microbes
- Oh Boy Astronomy’s Flippin’ Gnarly, Kool, Magical
- Our Best Alumni Found Gaining Knowledge Marvelous
- Oh Boy, Astronomers Found Giant Killer Moon
- One Billion American Females Go to Kickboxing Matches
- Oh brother another frat guy knocking monogamy
We also talked about how many of the scientists involved in this type or work and research were women . Yay! Like Williamina Fleming, Annie Jump Cannon, and Cecelia Payne-Gaposchkin.
I briefly described the HR-diagram (if I teacher this class again, I’ll spend more time on it), and the basic properties of the stars of each spectral class.
We then discussed the various techniques that we use to find extrasolar planets (direct imaging, astrometry, Doppler technique, gravitational lensing. and the Transit method). We spent quite a bit of time on the last one and the development of the Kepler Mission.
I describe the various types of planets that have been discovered (hot Jupiters, Super Earths, etc.), and if we believe Earth is a rare planet or not. Yes, if you are a proponent of the rare-Earth hypothesis.
I ended with talking about how we are looking for certain signatures in the atmospheres of planets to show an indication of life. (water, methane, etc.).
Throughout the lecture I had the students answer questions using virtual clickers. They also had the option of completing a min-lab on exoplanets.
Next week: what’s up with UFOs & alien abductions, SETI, and the Drake Equation.
Can’t believe there’s only 2 lectures left 😦