Reading the Dips: Light Curve Analysis Quiz

If a light curve is a graph that plots light intensity against time, then the data points allow us to see how the brightness of a celestial object fluctuates.

If scientists monitor the brightness of distant stars and see regular, repeating dips, then they can use light curve analysis to confirm the presence of an exoplanet.

If a planet passes between Earth and its host star, and if that planet blocks a portion of the star's light, then the observed brightness will decrease, creating a dip in the data.

If the term refers to the specific visual data recorded when a planet moves across a star, then the correct phrase is transit light curves.

If the graph shows when dips happen and how deep they are, then we can calculate the time between orbits (period) and the physical size (depth), though distance from Earth requires different measurements.

If the depth of a dip is determined by how much surface area of the star is blocked, and if a larger planet blocks more surface area than a smaller one, then a deeper dip indicates a larger planet.

If the dip is caused by a planet blocking light from reaching our telescopes, then the star's actual energy output hasn't changed; the decrease is only an "apparent" change due to the transit.

If the dips in a light curve occur at regular, repeating intervals, then that interval represents the time it takes for the planet to complete one full orbit around its star.

If astronomers use specialized scatter plots to look for signs of new exoplanets, then those visualizations are known as planet detection graphs.

If any opaque object or dark feature blocks starlight or if the telescope malfunctions, then the light curve will show a dip that could be mistaken for a planet.

If a planet takes time to move from one side of the star to the other, and if it stays completely within the star's disk for a while, then the brightness will remain at its lowest point, creating a flat bottom.

If a planet is moving faster, it will spend less time in front of the star; if it spends less time there, the dip on the light curve will be narrower (shorter duration).

If a light curve tracks changes as they occur over minutes, hours, or days, then the horizontal axis must represent the passage of time.

If each planet has a unique size and orbital speed, then each will create its own unique dip in the light curve, resulting in multiple, overlapping patterns.

If the goal is to find a planet, then an observer must be able to see repeating dips, measure their size, calculate the timing, and ignore random data spikes that aren't caused by a planet.

If "limb darkening" causes a star to look brighter in the middle than at the edges, then the amount of light blocked will change as the planet moves across different parts of the star, creating a U-shape.

If the purpose of the graph is to show how much light we receive, then the vertical axis must represent brightness (or flux).

If the dip represents a ratio of the planet's area to the star's area, and if the star's size is already known, then the math allows us to solve for the planet's radius.

If electronic interference or stellar activity creates random zig-zags in the data, then those fluctuations can mask the tiny signal of a small planet or create "false positives" that look like transits.

If light curves only provide a candidate planet, and if other things can cause dips, then scientists must use a second detection method (like measuring the star's wobble) to confirm the planet's mass and existence.