* Mass: This is the most fundamental property determined from a binary system. By observing the orbital period and the separation of the stars, we can apply Kepler's laws of planetary motion and Newton's law of gravitation to calculate the combined mass of the system. If we can also measure the individual velocities of the stars (using Doppler spectroscopy), we can determine the individual masses of each star.
* Radius: While not directly measured, the radius of a star in a binary system can be estimated. If one star eclipses the other (an eclipsing binary), the duration of the eclipse and the orbital parameters can help estimate the relative sizes of the stars.
* Luminosity: Combining the radius and surface temperature (see below), we can estimate the luminosity of each star in the system.
* Surface Temperature: The spectral type of a star, which is related to its surface temperature, can be determined by analyzing the light emitted from each star in the binary system.
* Age: The evolutionary stage of each star can be inferred from its mass and spectral type, giving clues about its age.
* Composition: Spectroscopic analysis of the light from each star can provide information about the elements present in their atmospheres, revealing their chemical composition.
* Rotation: The Doppler shift of spectral lines can be used to determine the rotational velocity of each star.
Important Note: The accuracy of these property estimations depends on the quality of the observations and the specific type of binary system.
