Survey
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* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Name: ______________________________________________ Extrasolar Planets Date: ___________________________ To answer the questions below go to: http://www.msnbc.msn.com/id/11022898 1. What is an exoplanet (or extrasolar planet)? An exoplanet/extrasolar planet is a planet either orbiting a star that is not the Sun or is simply drifting through space. 2. List and describe in your own words TWO of the four methods that astronomers use to find exoplanets. Do not copy the text word-for-word. Method 1: Astrometric detection Description: The movement of a planet’s parent star can be detected, indicating the gravitational pull of a massive non-stellar body. Method 2: Radial velocity Description: The parent star wobbles due to the gravity of the orbiting planet. The wobble causes shifts in the star’s emitted light’s wavelength. Method 3: Transit Description: A planet crosses in front of a star, dimming its light temporarily. Method 4: Microlensing Description: A gravity well warps light passing behind an extrasolar planet. 3. Look through some of the exoplanets on the “extrasolar planet finder.” What is the method that was used to locate the majority of the exoplanets? Radial velocity. Name: ______________________________________________ Extrasolar Planets Date: ___________________________ To answer the questions below go to: http://exoplanet.eu/catalog.php Important note: All planetary masses are listed by default in terms of Jupiter mass (MJup = 2.5 means a mass two and one half times greater than the mass of the planet Jupiter) and distances are listed in astronomical units (AU). 1. How many exoplanets have been discovered so far? 1919 as of 5/12/15. 3610 as of 5/16/17. 2. Of all the exoplanets listed, give the name of the planet that orbits the farthest from its central star and how far away the planet is from its star. HIP 77900 b is 3200 au from its parent star. 3. How does this most distant exoplanet listed compare in size to Jupiter and its distance from its central star? (Jupiter is 5.2 AU from the Sun) It’s 20 times more massive and 615.4 times farther away. 4. Of the exoplanets listed, list 3 (name & mass) that are most like that mass of the Earth (0.003 MJup). Kepler-42 d is 0.003 AU, Kepler-138 d is 0.0032 AU, and KOI-2700 b is 0.0027 AU. 5. Do any of the planets shown orbit closer than Mercury at 0.3 AU? Yes, many. 6. Switch the units for Mass (MJup) and Radius (RJup) to Earth units (MEarth and REarth). Do any of the known exoplanets have a mass and radius comparable to Earth? If none are exactly the same, which is closest? What values does it have? Kepler-42 d is the same mass as Earth, but orbits at 0.57 au. KOI-2700b is 86% of the mass and orbits only 1.06x further than Earth. Kepler-138 d and c are 1.01x the mass of Earth but orbit at 1.61x the distance.