How Do You Calculate the Mass of a Star in Orbit?

  • Thread starter Thread starter contlee
  • Start date Start date
  • Tags Tags
    Mass
AI Thread Summary
To calculate the mass of a star in orbit, the centripetal acceleration formula GM/R^2 is used, where G is the gravitational constant and M is the mass of the central body. The orbital velocity can be determined with V=2πR/T, leading to the equation GM=4π²R³/T², which calculates the mass of the central body rather than the orbiting star. If the central body is significantly more massive than the star, the calculated mass will primarily reflect the central body's mass. Conversely, if the star is more massive, the result will approximate the star's mass. The problem lacks specific details about the other body, leaving the intent unclear.
contlee
Messages
9
Reaction score
0

Homework Statement



Star A is in a circular orbit of radius R around point P. The period of the star is T. Determine the mass of the Star


Homework Equations


I do not know how to find the mass of the orbiting body. I found the centripetal acceleration which equaled GM/R^2. I could find the mass of P, but not the orbiting body


The Attempt at a Solution

I said that V=2piR/T. then that GM=4pi^2R^3/T^2. But that only gives me the mass of the body the star is orbiting around... Right?
 
Physics news on Phys.org
I think you're right, at least if you assume that the other body is much more massive than the star itself. Then again, if the other body is much lighter than the star, the mass you find is pretty close to the mass of the star. But the problem doesn't say anything about the other body, so I'm not sure what the intent is.

I'll bring this to the attention of other homework helpers and perhaps one of them will have some insight.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Similar threads

Calculate the mass of a star and a planet that orbits it
Replies
12
Views
3K
Time taken for a planet to collide with the Sun
Replies
10
Views
806
Speed of a star in Special Relativity
Replies
6
Views
1K
Calculate Mass of Satellite: Step-by-Step Guide
Replies
16
Views
3K
Two stars orbit their common center of mass
Replies
2
Views
1K
Planet moving in elliptical orbit around a star
Replies
13
Views
840
What is the Minimum Mass for a Rotating Neutron Star?
Replies
6
Views
2K
Circular orbit change after gaining mass ejected from sun
Replies
1
Views
1K
Calculating Angle & Speed to Reach Planet's Moon from Station Orbit
Replies
1
Views
2K
Two stars orbiting a common center
Replies
25
Views
3K

Hot Threads

Recent Insights

Back
Top