Searching for Life Outside Our Solar System
The universe may be teeming with life, or we might be the only example, we won’t know until we find it or we look everywhere. Only about 20 years ago, our star was the only one known to host a solar system. Now thousands of candidate extrasolar planets have been detected. These are planets that are orbiting stars other than our Sun. As this search continues, most scientists consider it nearly inevitable that other planets that could harbour life somewhere in the universe.
This session’s assignment let’s you “get your hands dirty” with the methods astronomers use to search for extrasolar planets.This assignment often takes students a bit longer, so start early and plan some time for it.
Basically, you are going to solve a puzzle and find which of the following data portfolios show evidence of an extrasolar planet. The methods are described in my Notes up. I have cleaned up the data for you, but it is tricky and takes some time to understand. You have honed your Internet research skills by now. Work with your group to crack the codes of the stars – but remember to write up your own assignment. Group write ups and borrowed text will not be accepted.
For this assignment you are going to practice some of the data analysis that astronomers have to do to look for evidence of extrasolar planets. You are given six example graphs of data that use three different methods: the astrometry method, the “wobble” or spectral method, and the transit method.
I have provided some notes in the reading section on each of these methods, using the same types of diagrams I provide for the assignment. You will also be able to find a lot online about these methods and the discoveries made with them.
There are two examples for each of three methods: Astrometry, Spectral, and Transit methods.
For each example you are to determine if there is sufficient evidence to claim that there is an extrasolar planet orbiting the star. You are going to do this six times, once for each of the graphs. They are not connected to each other.
Part 1 : For each graph answer (15% each) :
- Is there evidence of a possible extrasolar planet orbiting this star? (Yes or no)
- If there is not sufficient evidence to say there is an orbiting star, you should include a paragraph explaining why there is insufficient evidence of an extrasolar planet. There is no need to try to explain what could cause the patterns you do see in the data, but you have to explain why they are different than what you might see if there were a planet orbiting the star. (about 100 words)
- If there IS evidence of an extrasolar planet, you must include a paragraph about the evidence you used to come to that conclusion as well as the orbital period of the planet (how long it takes to make a complete orbit around the star). (about 100 words)
Part 2 (3 pts): Answer the following question (10%)
- Are any of these graphs likely from the same star? Explain your answer. Remember to think about the orbit and the way we view the star. (about 100 words)
Please submit in PDF or a current version of .docx (MS word) to the DROPBOX area under COURSE ACTIVITIES on the top menu bar. Our TA will grade them and should return them within 2 weeks. If you have trouble submitting, please email a copy of the assignment before the due date to get full credit.