How do you find the radius of a planet using the transit method?

To determine the planet radius, the brightness drop of the parent star that occurs during a planetary transit is measured. This brightness drop is directly related to the ratio of the planet radius to the radius of its parent star, as shown in the image below.

How do you find the orbital radius of a star?

Kepler’s Third law can be used to determine the orbital radius of the planet if the mass of the orbiting star is known (R3=T2−Mstar/Msun, the radius is in AU and the period is in earth years).

What information can we learn about an exoplanet and its host star from a Lightcurve?

Transit data are rich with information. By measuring the depth of the dip in brightness and knowing the size of the star, scientists can determine the size or radius of the planet.

How do we detect exoplanets using radial velocity?

The radial-velocity method for detecting exoplanets relies on the fact that a star does not remain completely stationary when it is orbited by a planet. The star moves, ever so slightly, in a small circle or ellipse, responding to the gravitational tug of its smaller companion.

How do you find the radius of an exoplanet?

By noting the time between the first and last dips in a light curve along the x-axis and dividing by the number of dips, the period of the exoplanet can be obtained. Measuring the drop in brightness along the y-axis allows calculation of the radius of the exoplanet and subsequently its volume.

How do you find an exoplanet using the transit method?

The transit method consists of regularly measuring the luminosity of a star in order to detect the periodic decrease in luminosity associated with the transit of an exoplanet. The transit happen when a planet passes in front of its star.

How do you calculate exoplanet mass?

To determine a planet’s mass, astronomers typically measure the minuscule movement of the star caused by the gravitational tug of an orbiting planet. For planets the mass of Earth detecting such a tiny tug is extraordinarily challenging with current technology.

What is the best technique of those below to determine the size radius of an exoplanet?

Radial velocity: The exoplanet is detected by measuring the Doppler shift in the host star light, a consequence of the gravitational affects between the two bodies. The technique is most sensitive to exoplanets with a large mass orbiting close to their host star perpendicular to the plane of the sky.

What is the transit method of finding exoplanets?

How do you find an exoplanet?

Bottom line: The most popular methods of discovering exoplanets are the transit method and the wobble method, also know as radial velocity. A few exoplanets have been discovered by direct imaging and microlensing.

How do you determine the radius of a planet during transit?

The remaining properties to be determined are radius and density. To determine the planet radius, the brightness drop of the parent star that occurs during a planetary transit is measured. This brightness drop is directly related to the ratio of the planet radius to the radius of its parent star, as shown in the image below.

How do I calculate the orbital period of an exoplanet?

The first calculation comes from Kepler’s Third Law (shown below), where ‘ G’ is Newton’s Gravitational Constant .The period, ‘ P’, is the orbital period of the exoplanet, and comes directly from the measured period using, for example, the transit or radial velocity detection methods ( Detection Methods page ).

How do you calculate the average density of an exoplanet?

Calculating the average density of the exoplanet is a simple matter of dividing the mass by the volume, where the volume is determined using the radius calculated above. What sort of conclusions can be made about an exoplanet given these properties?

How can we determine the distance of a planet from its stars?

Once the orbital period is known, Kepler’s Third Law of Planetary Motion can be applied to determine the average distance of the planet from its stars.