Question about Finding Mass of Visual Binaries with Given Information

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Discussion Overview

The discussion revolves around a homework question related to visual binaries in astronomy, specifically focusing on how to determine the masses of two stars given their combined mass and luminosity information. The scope includes conceptual understanding and mathematical reasoning related to binary star systems.

Discussion Character

  • Homework-related
  • Exploratory
  • Mathematical reasoning

Main Points Raised

  • One participant expresses uncertainty about how to find the individual masses of the stars, noting that the period may be relevant.
  • Another participant provides a method to estimate the mass of one star by referencing its classification as a main sequence star and using a radius vs mass diagram.
  • A participant discusses the measured positions of the stars relative to the center of mass, suggesting a method to infer the mass ratio based on their distances from the center of mass.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the method for determining the masses of the stars. Multiple approaches are presented, and the discussion remains unresolved regarding the best method to use.

Contextual Notes

The discussion includes assumptions about the relationship between luminosity, mass, and distance from the center of mass, but these are not fully explored or resolved.

pi-70679
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I have a question about visual binaries on a homework, which is at the link below.
http://pages.infinit.net/bdufou1/question2.jpg
In addition to what is written in the question, we know that the sum of both masses is 3.3 times the mass of the sun, and Luminosity of A is three times that of the sun. I don't have any problem finding the radius of both stars, but i have no clue how to find the mass of each. I'm pretty sure the period is involved, but how??
Can somebody help??
Thanks in advance
 
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Originally posted by pi-70679
I have a question about visual binaries on a homework, which is at the link below.
http://pages.infinit.net/bdufou1/question2.jpg
In addition to what is written in the question, we know that the sum of both masses is 3.3 times the mass of the sun, and Luminosity of A is three times that of the sun. I don't have any problem finding the radius of both stars, but i have no clue how to find the mass of each. I'm pretty sure the period is involved, but how??
Can somebody help??
Thanks in advance

I looked at the page and it has a sketch of the paths
from about 1935 to 1985.
I measured with a millimeter measure on my computer screen
and saw that A was 5 mm above the CM line around 1965 about the same time that B was, it looked like 11 mm, or even 12 mm, below the CM line.

You have a situation where the less massive partner is swinging out 2.2 or 2.3 times farther from CM than the more massive partner goes.

If it's not obvious to you what the ratio of masses is, write back.
 
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Thanks a lot, but i found another way of doing it. I found out that sirius A is a main sequence star, and form a diagram of radius vs mass of main sequence stars i approximated the mass and i have the same answer as the theoretical one. So i guess it works. I thought about measuring the distance but it was really non-trivial since it was such a bad drawing. But thanks anyway, i guess i'll see if my way is right when i'll get my assignment back.
 

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