Top

Task 1: Determining the Mass of Your Exoplanet

Find the velocity of the star.
An equation of the mass of the planet equals the mass of the star, provided by the star team multiplied by the velocity of the star, derived from radial velocity curve divided by the velocity of the planet, calculated with data provided by the star team and period team. Image points to and circles the velocity of the star, derived from radial velocity curve
image of a scientist

Look confusing? Don’t worry, you don’t have to do this math by hand! Input your numbers into the google sheet as directed below and the equations will be automatically calculated for you.

First, we need to find the radial velocity of the star. To do this, we will interpret data from a radial velocity curve graph of your exoplanet’s parent star.
Radial Velocity (m/s) graph by 0.84 phase
Measure the peak value on this graph to determine the maximum radial velocity of the star.
Write the velocity of the star in cell B4 of the Google Sheet.

the google sheet support

Receive the mass of the star.
An equation of the mass of the planet equals the mass of the star, provided by the star team multiplied by the velocity of the star, derived from radial velocity curve divided by the velocity of the planet, calculated with data provided by the star team and period team. Image points to the mass of star, provided by the star team
Next, request the mass of the star from the Host Star team. Send the following message in the chat.
“Mass team to Host Star team. The Mass team requests the mass of the Host Star in order to proceed.”
image for instructions for sending messages in the chat feature in Zoom. 1. Copy and paste the message from your task card to the chat. 2. Hit enter to send the message. 3. Unmute yoursself and read the message out loud to ensure that it is received. Make sure the message is being send to everyone

While you wait... did you know?

Watch the following video about how exoplanets get their names while you wait for the Host Star team to share the mass of the star. If you have already received the information you need, you may skip this video and continue working through your task card.

When you receive the mass of the star, send the following confirmation message to the Host Star team.

“Mass team to Host Star team. Data received. Thank you.”
Then, enter the mass of the star into cell B2 of the Google Sheet below.
Calculate the velocity of the planet.
An equation of the mass of the planet equals the mass of the star, provided by the star team multiplied by the velocity of the star, derived from radial velocity curve divided by the velocity of the planet, calculated with data provided by the star team and period team. Image points to and circles to the velocity of the planet, calculated with data provided by the star team and period team.
To calculate the velocity of the planet, you need the following variables:
star mass icon. orange backgrounf with a see-saw like image. Star is bigger on one side and planet is smaller on the other side. Arrow pointing to the star.
period icon. pink background image shows a curve of a period and how to measure it between two peaks in the a curve.
The velocity of the planet will be calculated using the following equation:
 
An equation. The velocity of the planet equals 2 times pi multiplied by the mass of the star, provided by the star team divided by the period of the planet, provided by the period team to the 1 divided by 3 power.
 
You have already received the mass of the star from the Host Star team. You will now need the planet’s period from the Period team to calculate the velocity of the planet.

Send the following message to the Period team in the chat. Click here for instructions on how to send messages.
“Mass team to Period team. The Mass team requests the period of the planet in order to proceed.”

while you wait... did you know?

Image of Planet 51 Pesgasi-b. While you wait, did you know in 1995 the first exoplanet orbiting a sun-like star was deteced using the radial velocity method!
When you receive the period of the planet, send the following message in the chat.

“Mass team to Period team. Data received. Thank you.”

Then, enter the data for the planet’s period into cell B3 of the Google Sheet below. The solution for planet velocity will be calculated automatically in cell B4.
The Google Sheet will now complete the following equation in order to determine the exoplanet's mass. The mass of the planet will be automatically calculated in cell B5 of the Google Sheet below.
 
An equation of the mass of the planet equals the mass of the star. multiplied by the velocity of the star, derived from radial velocity curve divided by the velocity of the planet.
 
Check cell B5 of the Google Sheet below to see the planet mass.
Planet Mass Planet Radius Planet Period Host Star Data Planet Volume Star Radius & Mass Planet Density Distance From Star Planet Composition In The Habitable Zone? Could This Planet Support Life?

You will share the planet mass with the following team:

radius team logo. red gradient in the shaped of a hexagon from the James Webb Space Telescope

If the Radius team has already requested the planet mass, send it in the chat now. If the Radius team has not yet sent a request, be prepared to send the information when the request arrives.

image of a scientist
Excellent work! You used some complicated formulas to calculate the mass of your exoplanet. With this information, you’re ready to collaborate with the Radius team to find the average planet density.