IOAA 2013, Отборен тур, хоризонтални въпроси — Задача 5. E

IOAA 2013 — Team Competition: Horizontal questions · 17 т.

Условие

i. A $A0V$ star has observed Colour Index $B-V=0.70$. How many times brighter would the star look if there was no interstellar extinction? Consider that $A_V = 3\times E_{B-V}$., where $E_{B-V}$ is the Colour Excess and $A_V$ is the Visual Absorption. (integer) [1 т.]

ii. The sidereal rotation period at the equator of the Sun (days). At the spectrum of the Sun, the line $H_{\alpha}$ ($\lambda$=6,563Å) has a broadening of 0.089Å. (integer) [2 т.]

iii. One star has a B-V colour index of 0.2mag and a U-B colour index of -0.1mag. What is its Colour Excess $E_{B-V}$? (one decimal) [2 т.]

iv. Chandrasekhar Mass limit in solar radii. (two decimals) [3 т.]

v. The orbital period of Mercury (days). (integer) [2 т.]

vi. The axial tilt of an exoplanet without atmosphere is $0^{\circ}$. Its orbital period is really long. How many times greater is the mean temperature of the illuminated (by the corresponding star) hemisphere when the planet spins really slowly compared to when it spins really quickly? (one decimal) [2 т.]

vii. The atomic mass (in a.m.u.) of the heaviest element which can be produced in a star, before it meets its end. [2 т.]

viii. Diameter of the biggest single aperture optical telescope in meters (integer) [2 т.]

ix. The inventor of the telescope.

1. Demisianos
2. Brache
3. Ibn Sahl
4. Lippershey
5. Huygens
6. Harriot
7. Marius
8. Newton
9. Galileo [1 т.]

Отговори

Решение

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Оригинал в Архива: Horizontal_questions.pdf