USAAAO 2026, I кръг — Задача 16

USAAAO 2026 - First Round · 9 февруари 2026 г.

Problem writers

Problem writers: Srihari (Hari) Balaji, Vincent Bian, Ferdinand, Hagan Hensley, Elizabeth Lee, Joe McCarty, Lucas Pinheiro, Feodor Yevtushenko

Условие

Kepler-22b is an exoplanet discovered by transiting with an orbital period of 290 days. Suppose it has a mass of $4.84\times10^{25}$ kg and a moon similar to Earth’s, with a prograde orbit near the ecliptic plane of the Kepler-22 system and a semi-major axis of $7.70\times10^{8}$ m. What is the length of a synodic lunar month, i.e., the time between successive full moons, for an observer on Kepler-22b? You can neglect the mass of the moon.

(a) 25.0 days

(b) 27.3 days

(c) 29.5 days

(d) 30.2 days

(e) 33.6 days

Отговори

Решение

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Оригинал в Архива: usaaao_first_exam_2026.pdf · официални решения: usaaao_first_exam_solutions_2026.pdf