USAAAO 2019, I кръг — Задача 12
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
The celestial coordinates of the Orion Nebula are RA , dec . Which of the following is closest to the time (local solar time) when the Orion Nebula would cross the meridian on the night of February 1st 2019? The date of the vernal equinox of 2019 is March 20th.
A. 08:40 PM
B. 10:22 PM
C. 12:00 AM
D. 01:38 AM
E. 03:20 AM
Отговори
08:40 PM
The key's working gives past noon and then states 08:40 PM.
Решение
Solution: A; 08:40 PM
February 1st is 47 days before the vernal equinox, so the RA of the sun is
The Orion Nebula therefore crosses the meridian
past noon, or 08:40 PM.
Оригинал в Архива: 2019_usaaao_first_round.pdf · официални решения: usaaao_first_round_answer_key.pdf