exoplanet_struct.md

What is the Exoplanet struct?

The Exoplanet struct is used as the return value of the FindPlanet class. It contains important information about the exoplanet detected such as the orbital period of the planet.

Data contained in the Exoplanet struct

The Exoplanet struct contains four main getter methods:

• float averageFlux(): The average normalized flux of the planet. Normalized flux means that 1 = average brightness of the star and 0 = no light is reaching the sensor.
• float averagePeriod(): The average orbital period of the planet.
• Lightcurve datapoints(): Specific datapoints the program found from the planet.
• float confidence(): Percent confidence of an exoplanet between 0 and 1. Note that "1" does not mean that it is certain to be an exoplanet, but the program thinks it is probable to be an exoplanet.

Find the Semi-Major Axis

To find the semi-major axis of the orbit in astronomical units (AU), call the method findSemiMajAxis(float solarMasses), which returns the semi-major axis of the exoplanet as a float.

ExoSpotter::Exoplanet myExoplanet = ...;

// the star's mass in solar masses
float starMass = 2.3;

// the semi major axis of the planet in AU
float semiMajAxis = myExoplanet.findSemiMajAxis(starMass); 

Find the radius ratio

To find the ratio between the planet's radius and the host star's radius, use the findRadiusRatio() method. If the ratio cannot be found (usually due to a division by zero error), the method will return -1.

Usage looks like the following:

#include "include/exoSpotter/exoSpotter.h"

int main()
{
    ExoSpotter::Exoplanet myExoplanet = ...;

    const float starRadius = ...  // optional: the host star's radius
    float radiusRatio = myExoplanet.findRadiusRatio();

    if (radiusRatio != -1) {  // if there is no issue
        float planetRadius = radiusRatio * starRadius;  // find the radius of the planet in the units given for starRadius
    }
}

Constructor

When working on developing the library, it is essential to fully understand the values of the Exoplanet constructor. However, if you are only using this library and not developing it, this is not required to know.

The Exoplanet struct only requires a Lightcurve struct.

Here is an example of initializing the Exoplanet struct:

#include "include/exoSpotter/exoSpotter.h"

int main()
{
    // Create a lightcurve struct to input into the Exoplanet constructor.
    // If you haven't already, see parse_data.md to understand how to
    // parse data into a Lightcurve struct.
    ExoSpotter::Lightcurve planetData{ ... };

    ExoSpotter::Exoplanet myExoplanet{ planetData };

    return 0;
}