USAAAO 2019, I кръг — Задача 11
USAAAO National Astronomy Olympiad First Round 01/26/2019-02/01/2019 · 26 януари 2019 г. · 1 т.
Указания
This exam contains 8 pages and 30 questions. Each question is worth 1 point, so there are 30 points total. Students MUST take the exam between 01/26/2019-02/01/2019. Proctors must scan students’ responses by 11:59 pm PST on 02/01/2019.
PHYSICAL AND ASTRONOMICAL CONSTANTS
| c | Speed of light in vacuo | |
| e | Elementary charge | |
| m | Neutron rest mass | |
| m | Proton rest mass | |
| m | Electron rest mass | |
| h | Planck’s constant | |
| Dirac’s constant () | ||
| k | Boltzmann’s constant | |
| G | Gravitational constant | |
| Stefan-Boltzmann constant | ||
| c | First Radiation Constant () | |
| c | Second Radiation Constant () | |
| Permittivity of free space | ||
| Permeability of free space | ||
| N | Avogadro constant | |
| R | Gas constant | |
| a | Bohr radius | |
| Bohr magneton | ||
| Fine structure constant () | ||
| M | Solar mass | |
| R | Solar radius | |
| L | Solar luminosity | |
| T | Solar temperature | 5770 K |
| M | Earth mass | |
| R | Mean Earth radius | |
| R | Mean Mars radius | |
| 1 light year | ||
| 1 AU | Astronomical Unit | |
| 1 pc | Parsec | |
| 1 year | ||
| 1 erg |
ENERGY CONVERSION : 1 joule (J) = electronvolts (eV)
Условие
Whether or not a diffraction-limited optical system is able to resolve two points as distinct can be determined by the Rayleigh criterion. Pictoris b is one of the first exoplanets discovered using direct imaging. The star system is located 19.44 pc away, and Pictoris b is located 9.2 AU from the host star. When viewing in infrared ( nm), what is the minimum telescope diameter that is able to resolve Pictoris and its exoplanet under the Rayleigh criterion?
A. 0.719 m
B. 0.877 m
C. 1.142 m
D. 1.438 m
E. 1.755 m
Отговори
- 0.877 m
Решение
Solution: B: 0.877 m
The Rayleigh criterion states that two objects can be resolved if their angular separation exhibits the relation
where is the telescope diameter, so
Under the small angle approximation, the angular separation between Pictoris and its exoplanet is
where is the distance from Earth to the system. Therefore,
Оригинал в Архива: 2019_usaaao_first_round.pdf · официални решения: usaaao_first_round_answer_key.pdf