Getting Aquainted With the Interactive Catalog at Exoplanet.eu
Data Catalog
*What is the most massive exoplanet found so far?
______
*What is the longest orbital period of all of the exoplanets found?
______
*What is the name of the most recently updated exoplanet?
______
*When was it updated?
(European dates are written Day/Month/Year) ______
*NASA’s Kepler Mission is defining Earth-type exoplanets to be those in between 0.5 and 2.0 Earth masses (0.0016 – 0.0063 Jupiter masses), or those between 0.8 and 1.3 Earth radii (0.0714 – 0.116 Jupiter radii). How many of the exoplanets found fit either of these qualifications?
Earth-type mass: ______
Earth-type radius: ______
(Note: The Kepler Mission’s approach to finding exoplanets will reveal the exoplanet’s radius and other physical characteristics with much more detail [the telescope became operational in Summer 2009] -
Histograms
*How many exoplanets have an orbital eccentricity (Planet Ecc.) greater than 0.5 ?
______
*How many exoplanets were found in 2007?
______
(The next two questions use the Pie-chart Display)
*What percentage of all exoplanets found occurred in 2007?
______
*What percentage of all the exoplanets less massive than Jupiter are less than 0.1 Mj? (Hint: in the Max filter, enter “1”)
______
Correlation Diagrams
*What two variables should you plot to find denser (rocky) exoplanets?
______
*There are two ways to plot the data on each axis (linear and logarithmic). For ‘planet mass’ do you get better detail when you plot with linear or logarithmic data points?
______
*All of the rocky planets in our Solar System are at least 3 times more dense than Jupiter. Does it look like we’ve found very many or very few rocky exoplanets?
______
*White dwarf stars have a mass that is comparable to the Sun, but are about 100 times smaller. Have we found any planets around white dwarf stars?
______
*There is a theoretical distance (Semi-major axis) from each star called the “habitable zone” where an exoplanet would have to orbit in order to support life as we know it (due to temperature). As a general rule, the “habitable zone” for more massive stars is further away than for less massive stars. What two variables should you plot to see if any planets could be in their star’s “habitable zone”?
______
*You already know the general “habitable zone” for a star with the Sun’s mass (Msun=1), Earth is orbiting at 1 AU. Knowing this much, do any of the exoplanets appear to be in the “habitable zone”?
______
Explanations of Units
-Mass of planets is given in Jupiter masses where 1 Jupiter is about 318 Earth masses (MJ = 1.90 x 1027 kilograms)
-Radius of planets is given in Jupiter radii where 1 Jupiter radii is about 11.2 Earth radii (RJ = 71,492 kilometers)
-Period of orbit is given in Earth days
-Semi-major axis is given in AU (astronomical units, where 1 AU = average distance of sun to Earth = 1.5 x 1011 meters)
-Metallicity indicates what fraction (relative to the most abundant element, Hydrogen) of a particular metal is present in a star's atmosphere normalized to that of the sun. The stellar metallicity of a particular element, X, is defined as the ratio of the amount of X (by number) to the amount of hydrogen in the star divided by the ratio of the amount of X to the amount of hydrogen in the Sun. This value is denoted as [X/H] and it is expressed in a logarithmic scale. [X/H] = Log10( (X/H)star / (X/H)Sun ). Therefore, a value of 0.0 is equal to the sun, greater than zero are metal rich, and less are known as metal poor. (For astronomers, metals are all elements heavier than H and He.)
-Stellar masses and radii are in solar units (MSun = 1.99 x 1030 kilograms) (RSun = 6.95 x 106 kilometers)
-Stellar distances are in parsecs where 1 pc = 3 x 1016 m or 3.26 light years.
-Angular distances are in seconds of arc.