IAO 2004, Всички кръгове — Задача 8. β2. Cometary bodies
IX International Astronomy Olympiad · 1 октомври 2004 г.
Внимание: Бележка към темата
Old photocopy scan. Two short passages of the official solutions are lost where the photocopied pages join (problem 4 between pages 4 and 5, the Sunrise solution between pages 13 and 14). The sky maps of the observational round are not in the archive file.
Условие
During an observation of a solar eclipse the observers discovered two cometary bodies in the constellation of Aries near the solar corona at an angular distance of from each other. Further researches have shown that these two bodies are moving along exactly the same path, at the detection time they were in the aphelion of their orbit (distance from the Sun a.u.), and in perihelion the distance from the Sun is equal to a.u.
Will these bodies be visible to any observer on the Earth during their nearest transit of perihelion? In what constellation will they be? The answer has to be explained by necessary formulae and numerical calculations. (Note: answer «Да-Yes» or «Нет-No» has to be written in English or Russian.)
Отговори
- Да-Yes; in Libra (the constellation opposite to Aries)
Решение
The major semi-axis of the orbit of the cometary bodies is a.u. It means, according to Kepler's Third Law, that they make a full revolution around the Sun during years. Thus, they will be in perihelion years later. Therefore, the Earth at this moment will be at the same point, as during the discovery, and the bodies – at a point opposite in ecliptic longitude. As during the discovery the bodies were in conjunction with the Sun (or very close to this position), in the perihelion they will be in opposition and so they can be observed. Answer: Да-Yes. They will be in constellation opposite to Aries, that is in Libra.
Group α, theoretical round
Data from the “Table of planetary data” may be used for the solving of every problem.
And the White Bear and Penguin are waiting for you on the practical round.
Group β, theoretical round
Data from the “Table of planetary data” may be used for the solving of every problem.
And the White Bear and Penguin are waiting for you in the practical round.
Parameters of orbits. Physical characteristics of some planets, Moon and Sun
Элементы орбит. Физические характеристики некоторых планет, Луны и Солнца
| Body, planet | Average distance to central body, in astr. units | Average distance to central body, in mln. km | Sidereal (or analogous) period, in trop. years | Sidereal (or analogous) period, in days | Eccentricity e | Equat. diameter, km | Mass, kg | Av. density, g/cm | Grav. acceler. at surf., m/s | Max. magn. from Earth **) | Albedo |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Солнце Sun | 1392000 | 1989000 | 1,409 | ||||||||
| Меркурий Mercury | 0,387 | 57,9 | 0,241 | 87,97 | 0,206 | 4 879 | 0,3302 | 5,43 | 3,70 | 0,06 | |
| Венера Venus | 0,723 | 108,2 | 0,615 | 224,70 | 0,007 | 12 104 | 4,8690 | 5,24 | 8,87 | 0,78 | |
| Земля Earth | 1,000 | 149,6 | 1,000 | 365,26 | 0,017 | 12 756 | 5,9742 | 5,515 | 9,81 | 0,36 | |
| Луна Moon | 0,00257 | 0,38440 | 0,0748 | 27,3217 | 0,055 | 3 475 | 0,0735 | 3,34 | 1,62 | 0,07 |
**) Для внешних планет и Луны – в среднем противостоянии.
**) For outer planets and Moon – in mean opposition.
Оригинал в Архива: iao2004.pdf