<p>The period (at least in physics) is defined the time an oscilating system needs to get back to its starting point (for a sinus curve its 2*pi).</p>

<p>Now when they say an eclipsing binary has a period of T years, it means that its brightness varies as seen from earth when they are eclipsing (thats how we detect eclipsing stars and planets by the way), and that the curve of its brightness is like an oscilation that gets back to its starting point every T years.</p>

<p>The meaning of this is, that this system consisting of 2 stars will be exactly as you see it now again in T years.</p>

CC BY-SA 3.0
2016-08-03T12:03:00.457Z
2016-08-03T12:03:00.457Z
RononDex
<p>I am confused about the definition of the period of an eclipsing binary, a binary configuration where one component crosses the other across the line of sight. When people say that an eclipsing binary has a period of T years do they mean that the period of the individual component is T years?</p>

CC BY-SA 3.0
2016-07-28T17:48:16.423Z
No idea where your confusion could be? Both components orbit the centre of mass with the same period.
ProfRob
CC BY-SA 3.0
2016-07-29T17:40:48.037Z
In binary star configurations, both stars orbit each other with the same period. When they say the eclipsing binary has a period of T years, they mean that both stars complete one orbit in T years and that implies that the eclipse will occur every T years.
zephyr
<time-domain-astronomy><eclipsing-star-systems>
period of an eclipsing binary
Orbifold
# period of an eclipsing binary

(Asked by: username_0 on 2016-07-28)

I am confused about the definition of the period of an eclipsing binary, a binary configuration where one component crosses the other across the line of sight. When people say that an eclipsing binary has a period of T years do they mean that the period of the individual component is T years?

**Tags:** time-domain-astronomy, eclipsing-star-systems
> **Comments:**
> **username_1**: No idea where your confusion could be? Both components orbit the centre of mass with the same period.  
> **username_2**: In binary star configurations, both stars orbit each other with the same period. When they say the eclipsing binary has a period of T years, they mean that both stars complete one orbit in T years and that implies that the eclipse will occur every T years.  

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## 1 answers

### Answer by username_3 on 2016-08-03. Score: 2

The period (at least in physics) is defined the time an oscilating system needs to get back to its starting point (for a sinus curve its 2\*pi).

Now when they say an eclipsing binary has a period of T years, it means that its brightness varies as seen from earth when they are eclipsing (thats how we detect eclipsing stars and planets by the way), and that the curve of its brightness is like an oscilation that gets back to its starting point every T years.

The meaning of this is, that this system consisting of 2 stars will be exactly as you see it now again in T years.


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