Lefatše ke eng?
International Astronomical Union (IAU) e hlalositse ka Phato 2006, hore polanete tsamaisong ea letsatsi ke'mele oa leholimo o: - e potoloha Letsatsi (naleli ea tsamaiso ea letsatsi), - e na le boima bo lekaneng ho nka sebopeho sa hydrostatic equilibrium (hoo e batlang e le se chitja), - e khōlō ka ho lekaneng hore matla a eona a khoheli a tlose lintho tse ling tsa boholo bo tšoanang haufi le tsela eo e potolohang letsatsi ka eona.