IAO 2015, Практически тур, Група β — Задача 6. The extinction in terrestrial atmosphere
XX Международная астрономическая олимпиада / XX International Astronomy Olympiad, Россия, Татарстан, Казань, 15 – 23. X. 2015 / Kazan, Tatarstan, Russia — Round: Prac, Group: β · 15 октомври 2015 г.
Requirements
Languages of the solutions. (For Practical and also for Observational rounds). No text in any language is permitted to use in solutions. All the solution must be written using only drawing pictures, plotting graph, writing formulae, numerical values and standard international astronomy symbols (like ♂, ♎, α UMa, M31, ). Numerical values must be written using standard symbols but not symbols of National alphabet. Jury of the Practical round will not take into account any text in any language in solution.
For example, the names of constellations, written in English, Russian or any other language will be not taken into account (should be only UMa, Ori, etc.).
Требования
Языки написания решений задач. (На практическом и наблюдательном турах). Тексты в решениях не допускаются (ни на каком языке). Все решения должны содержать только рисунки, графики, формулы, численные значения и стандартные международные астрономические символы (такие как ♂, ♎, α UMa, M31, ). Цифры должны быть написаны стандартными символами (не символами национального алфавита). Жюри практического тура не будет учитывать какие-либо тексты (на любом языке) в решении.
Например, не учитываются названия созвездий, написанные на английском, русском или любом другом языке (должно быть только UMa, Ori и т.д.).
Условие
Extinction is a term used in astronomy to describe light attenuation due to its absorption and scattering.
A star was observed at different zenith distances during one night at the Engelgardt's Astronomical Observatory in the program of atmospheric extinction study at blue. Astronomers use parameter X, air mass, as an extinction characteristic. This parameter corresponds to relative length of the ray's way in the atmosphere. That means X = 1 for zenith, X = 2/3 for z = 30º; X = 2 for z = 60º and so on.
The determination of the star's brightness was performed with the method of photon counting. The 3rd column includes number n – the quantity of photons which were detected during one second. A luminescent source was used for calibration the data of observations. It produces a stable flow of photons N = 9900 ± 100 per second, which is equal to magnitude mb = 9.64 beyond the terrestrial atmosphere.
| z | X | n | Δmb |
|---|---|---|---|
| 39.7 | 15135 | ||
| 45.6 | 13816 | ||
| 49.5 | 13180 | ||
| 53.0 | 12246 | ||
| 54.9 | 11800 | ||
| 58.2 | 10089 |
6.1.
Draw the table (similar to that you see right) in your answer book. Calculate the air mass for given zenith distances in 1st column, and write the result into the 2nd column.
6.2.
Calculate relative magnitude of the star Δmb (blue), and write the result into the 4th column. Use the luminescent source as standard for the relative magnitudes.
6.3.
Find functional relation between Δmb and X with a help of graphical method.
6.4.
Determine the magnitude of this star as it was observed in zenith.
Решение
Внимание: Непълно решение
No official practical solution or grading key is present in the complete 2015 archive inventory.
Оригинал в Архива: pract_beta.pdf · допълнителни данни: pract_instr.pdf · допълнителни данни: pract_beta_data.pdf