perihelial
/ˌpɛrɪˈhiliəl/
adjective
- Relating to the point in an orbit around the sun where an object is closest to the sun.
- Perihelial distances vary for different comets depending on their orbits.
- Astronomers calculated the perihelial speed of the asteroid as it neared the sun.
- The spacecraft made its perihelial approach, gathering data on solar radiation.