Package nightfall-1.62-4

Nightfall can produce animated views of eclipsing binary stars, calculate synthetic lightcurves and radial velocity curves, and eventually determine the best-fit model for a given set of observational data of an eclipsing binary star system. Nightfall is based on a physical model that takes into account the nonspherical shape of stars in close binary systems, as well as mutual irradiance of both stars, and a number of additional physical effects. Nightfall can handle a large range of configurations, including overcontact (common envelope) systems, eccentric (non-circular) orbits, surface spots and asynchroneous rotation (stars rotating slower or faster than the orbital period), and the possible existence of a third star in the system ('third light'). Refereed papers where Nightfall is used: Covino et al. 2000, Astron. Astrophys. 361, L49