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 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
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
760
Speed of a star in Special Relativity
Replies
6
Views
1K
Calculate Mass of Satellite: Step-by-Step Guide
Replies
16
Views
2K
Two stars orbit their common center of mass
Replies
2
Views
1K
Planet moving in elliptical orbit around a star
Replies
13
Views
802
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