A light curve is the measurement of a celestial body's brightness at certain intervals and over a given period of time (hours, days, months...). Asteroids shine due to the Sun's light reflecting off their surface, and their brightness might vary due to one or more of the following factors: The asteroid's distance to us is changing (closer objects appear brighter). The asteroid's phase, just like the Moon's, is changing as it orbits around the Sun (the larger the area of the asteroid that is illuminated, as seen from Earth, the brighter it will appear). The asteroid, because of its irregular shape, reflects light differently as it spins. If the orbit of an asteroid is well known, the first two effects can be numerically calculated and their contributions removed from the measured light curve. We are then left with a light curve whose changes are due solely to the spinning of the asteroid.
14 Her b radius
You can learn more about it in this link .