IOAA 2009, Теория — Задача 14
3rd International Olympiad on Astronomy and Astrophysics — Theoretical Competition · 10 т.
Внимание: Бележка към темата
The problem PDF's constants table has missing equation glyphs; the intact matching table and logarithm formula were recovered from original proceedings PDF 41, explicitly attributed. The full 147-page proceedings file and hash are retained, with a declared reading scope of 41 and47–67. Printed solution inconsistencies are retained and annotated: Q10 intermediate omits field factor/unit; Q12 negative sign and 3.21/3.19 mismatch; Q15 signed −1.5 and referenced but absent Figures 1/2; Q16(d) denominator minus sign; Q17 final m−5.2 versus preceding m+5.2. No missing figure or correction was invented.
Please read these instructions carefully
- Each student will receive problem sheets in English and/or in his/her native language.
- The available time for answering theoretical problems is 5 hours. You will have 15 short problems (Theoretical Part 1, Problem 1 to 15), and 2 long problems (Theoretical Part 2, Problem 16 and 17).
- Use only the pen that has been provided on your desk.
- Do Not use the back side of your writing sheets. Write only inside the boxed area.
- Yellow scratch papers are not considered in marking.
- Begin answering each problem in separate sheet.
- Fill in the boxes at the top of each sheet of your paper with your "country name", your "student code", "problem number", and total number of pages which is used to answer to that problem.
- Write the final answer for each problem in the box, labeled "Answer Sheet".
- Starting and the end of the exam will be announced by ringing a bell.
- The final answer in each question part must be accompanied by units, which should be in SI or appropriate units. 20% of the marks available for that part will be deducted for a correct answer without units.
- The required numerical accuracy for the final answer depends on the number of significant figures given in the data values in the problem. 20% of the marks available for the final answer in each question part will be deducted for answers without required accuracy as given in the problem. Use the constant values exactly as given in the table of constants.
- At the end of the exam put all papers, including scratch papers, inside the envelope and leave everything on your desk.
Table of Constants
The problem PDF's constants table has missing embedded equation glyphs. This table and useful formula are transcribed from the matching intact table on original PDF page 41 of IOAA2009_final.pdf (printed page 36), retaining the full proceedings source and its original page numbering.
(All constants are in SI)
| Parameter | Symbol | Value |
|---|---|---|
| Gravitational constant | ||
| Plank constant | ||
| Speed of light | ||
| Solar Mass | ||
| Solar radius | ||
| Solar luminosity | ||
| Apparent solar magnitude (V) | ||
| Solar constant | ||
| Mass of the Earth | ||
| Radius of the Earth | ||
| Mean density of the Earth | ||
| Gravitational acceleration at sea level | ||
| Tropical year | 365.24 days | |
| Sidereal year | 365.26 days | |
| Sidereal day | 86164 s | |
| Inclination of the equator with respect to the ecliptic | ||
| Parsec | pc | |
| Light year | ly | |
| Astronomical Unit | AU | |
| Solar distance from the center of the Galaxy | ||
| Hubble constant | ||
| Mass of electron | ||
| Mass of proton | ||
| Central wavelength of V-band | ||
| Refraction of star light at horizon | ||
| 3.1416 |
Useful mathematical formula:
Условие
A satellite is orbiting around the Earth in a circular orbit in the plane of the equator. An observer in Tehran at the latitude of observes that the satellite has a zenith angle of , when it transits the local meridian. Calculate the distance of the satellite from the center of the Earth (in the Earth radius unit).
Отговори
Решение
In the figure, the observer is at and the satellite is in the angle will be
(2 points)
(3 points)
In EOS triangle we have:
(3 points)
(2 points)
[Observer O, Earth centre E and satellite S.]

Теми и трудност
Трудност: неоценена.
Небесна сфера и сферична астрономия · Небесна механика · Небесни координати · Орбитално движение
Предпоставки: Разширена олимпиадна подготовка
Оригинал в Архива: 2009_Theory.pdf · официални решения: IOAA2009_final.pdf