LAB 09 - EXOPLANETS NAME ____________________________ CLASS (CIRCLE ONE) DAY NIGHT DATE ____________________________ INTRODUCTION In this lab, you are going to use real data obtained from observations of exoplanets to determine their orbital characteristics. An exoplanet is a planet that orbits another star (i.e. they are planets that do not orbit our sun). There are many methods used to detect exoplanets, but the most successful has been the transit method. In this method, the planet’s orbit is aligned such that, as it moves between us and its parent star, it blocks a small amount of the light from that star. The amount of starlight that is blocked is extremely small and requires many careful observations to discern. There are many current and past observation projects dedicated to the search for exoplanets. PROCEDURES Go to the premier online repository of exoplanetary data at http://www.exoplanet.eu/catalog/ and use the ​ search feature to complete the table below. Input the name of each star into the Planet Search feature on the page and it will filter the list to show you the planets that are known to be part of that star system. For each star system, you will record the following information: ● Star Name - Record the star’s name in the first column. ● Planet Letter - The first planet will be designated “b” the next one “c” and so on. For example, first planet in the 16 Cygni system is called 16 Cygni b. ● Mass - The number you see in the table is a multiple of the mass of Jupiter (MJupiter). So, a mass less ​ ​ than 1 means it has less mass than Jupiter. Likewise, a mass value larger than 1 means it has a mass larger than Jupiter. ● Radius - The number you see in the table is a multiple of the radius of Jupiter (RJupiter) so this gives ​ ​ you some idea of the size of the planet. ● Period (days) - This is the orbital period (time to go around the star) in days. ● Period (years) - To get this number, divide the period in days by 365.25 to convert to Earth years. ● a - This is the average distance between planet and star in astronomical units (AU). ● e - This is the eccentricity of the planet’s orbit around the star. An e = 0 is a perfect circle, while a e = 1 is a line. So, your eccentricity values are going to between these values. A planet with an e value near zero is said to have a nearly circular orbit while a planet with an e value near 1 is said to ​ ​ have a highly elongated orbit. ​ ​ Search for the following stars at http://www.exoplanet.eu/catalog/ and complete the table that follows. ​ ​ ● 51 PEG << Done as an example. ​ ​ ● HD 69830 ● HD 190360 ● GLIESE 357 ● KEPLER-444 ● EPS ERIDANI TABLE OF SELECTED EXOPLANETS PLANET MASS RADIUS PERIOD PERIOD STAR NAME a e LETTER (MJUPITER) (RJupiter) (DAYS) (YEARS) ​ ​ ​ ​ 51 Peg b 0.47 1.9 4.2308 0.0116 0.052 0.0069 QUESTIONS 1. Did any of these star systems resemble the arrangement of planets found in our own solar system? If so, in what ways? 2. In what ways were these planetary systems (in general) different from our solar system? 3. Go back to http://www.exoplanet.eu/catalog/ and look for information on the most recently recorded ​ ​ exoplanet. What is known and unknown about this far off world? .