IAO 2015, Практически тур, Група α — Задача 7. Variable star.
XX International Astronomy Olympiad — Practical round. Problems to solve · 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 ином языке (должно быть только UMa, Ori и т.д.).
Условие
A variable star was explored at the RTT-150 Russian-Turkish telescope in 2003. The observations were performed during whole night at the first time, the 1st table. The brightness of the variable star was measured occasionally during the other nights, and moments of maximal values of brightness () were received on nights 2–5, the 2nd table. The time is in Julian days, and mv is the yellow spectral colour magnitude.
Table 1
| JD | mv |
|---|---|
| 2452805.3543 | 16.67 |
| 2452805.3712 | 16.57 |
| 2452805.3869 | 16.03 |
| 2452805.4026 | 15.69 |
| 2452805.4161 | 15.59 |
| 2452805.4512 | 15.80 |
| 2452805.5152 | 16.14 |
| 2452805.5848 | 16.32 |
| 2452805.6676 | 16.58 |
| 2452805.7734 | 16.68 |
| 2452805.8421 | 16.63 |
| 2452805.8643 | 16.62 |
| 2452805.9068 | 16.73 |
Table 2
| N | JDmax | mv |
|---|---|---|
| 1 | 15.59 | |
| 2 | 2452830.5089 | 15.59 |
| 3 | 2452831.5772 | 15.59 |
| 4 | 2452839.5858 | 15.59 |
| 5 | 2452854.5340 | 15.59 |
7.1.
Plot the light curve (magnitude vs time function), determine the moment of maximum in the first night and write result (in Julian days) in form of «T0 = …».
7.2.
Calculate the period of the variable star using the data of all 5 nights. Here period means the time between two closest maximums of the brightness. But actually astronomers usually do not know how many periods were passed between two observed maximums, because appropriate weather can not be same every day and a few periods can pass between two observed maximums.
7.3.
What type of variable star is this – eclipsing binary or pulsating variable star. (Write in English: Eclipsing or Pulsating respectively.)
Решение
Внимание: Непълно решение
No official practical solution or grading key is present in the complete 2015 archive inventory.
Оригинал в Архива: pract_alpha.pdf · допълнителни данни: pract_instr.pdf