Semi-major axis is the sum of the periapsis and apoapsis distances divided by two. For classic two-body orbits, the semi-major axis is the distance between the centers of the bodies, not the distance ...

Chinese astronomers have employed NASA's Transiting Exoplanet Survey Satellite (TESS) to observe an eclipsing binary of the Algol-type, designated V455 Car. Results of the observational campaign are ...

These are small rocky objects whose orbits are well beyond that of Neptune’s and have a semi-major axis (average orbital distance) of 150-250 AU (Astronomical Units, with 1 AU equaling ...