Which is NOT true about binary stars? They move about a common center of mass
They are always of equal brightness
They usually appear as one star
They are the most common stars in the galaxy

They are always of equil brightness.

Explanation:

the transfer of energy between two molecules spaced just nanometers apart plays a key role in many technologies, including photovoltaics, quantum information systems, lighting, and sensors, as well as in biophysics to measure nanometer distances and in photosynthesis. but an open question in this area is what effect, if any, the surrounding photonic environment has on this nanoscale energy transfer. by designing and performing a carefully controlled experiment to answer this question, scientists have settled the debate and found clues to improving the efficiency of many of the technologies that rely on this process.

explanation:

the farther away the object is from the central star (the sun) it's gravitainal pull on the object is weaker when it is farther

explanation: