A. The Parent Star
B. The Exoplanet|
The graph plots the un-calibrated signal minus the average signal from the instrument. When a planet passes in front of the star (making a transit across the star), the total light output drops accordingly. This causes the larger observed dips in the graph.
Note #1: If desirable, the plot may be printed so that the data may be measured more accurately. Simply click on the graph and then print the resulting web page.
Note #2: If no transits are observable in the data, then go beack to the previous page and select a different star.
A. Period of the Exoplanet
From the graph above, calculate the average time between transits of the planet across the star face. (Find the day of the first and last transit and divide by the number of time intervals between these transits.) Then enter this period in days in the formula below.
B. Distance of the Exoplanet from Its Parent Star
The third law of planetary motion derived by Johannes Kepler (and modified by Isaac Newton) connects the orbital period of a planet in our solar system, the mass of the Sun and the planet's average distance from the Sun.
Astronomers have been able to estimate the mass of a star if it is a main sequence star (on the H-R diagram) and if its spectral type is known. See the table.
Stellar Masses (in units of solar masses)
Locate the spectral type for this star and read off its mass. Then enter this number in the appropriate empty box below.
Kepler's third law can be written as:
|p2 M = a3|
Notes on the Photometric Observations
Notes on Kepler's Third Law
Simulation Authors: Richard L. Bowman (Bridgewater College) and David Koch (Kepler Mission)
Maintained by: Richard L. Bowman firstname.lastname@example.org (2002-04; last updated: 19-Apr-04)