Euro-Asian Astronomical Society

The First (Experimental) International Astronomy Olympiad

The following olympic problems were proposed for the participants on the theoretical part:

1. Why is it sometimes better to use a small telescope in orbit around the Earth than it is to use a large telescope on a mountain top?

2. A thick black fly has dotten onto the object lens of a 5 cm telescope. What will an observer looking to the Moon through the telescope see?

3. Explain why we see more meteors from midnight to dawn than from evening to midnight.

4. The 12 Zodiacal signs are equally extended on the ecliptic. In which of them does the Sun lie in for the shortest period?

5. On 1 cm2 of Pluto's surface fall approximately 10,000 photons per second from a star of the fifth magnitude. How many photons would fall on a detector from a star of 20m during half an hour, if BTA at the Earth is used (the diameter of the main mirror is 6 m)?

6. The sun has a parallax of ps = 8".8, and a star with the same absolute brightness - p* = 0".022. Is it possible to observe the star at night sky visually?

7. The moon set in St.Petersburg (60œ North, 30œ East) yesterday just at midnight. In what region of the Earth will there be an opportunity to observe a total solar eclipse sometime next week?

8. A spaceship landed on an asteroid 2.2 km in diameter with an average density of 2.2 g/cm3. The asteroid is slowly rotating. The cosmonauts decided to travel along the equator of the asteroid in a rover in 2.2 hours. Will it be possible for them to do such a thing? If the answer is negative, why? If the answer is positive, what do they take into account?

1. Why might some stars appear double in blue light through they could not be resolved in red light?

2. Why can radio astronomers observe during the day, whereas optical astronomers are (for the most part) limited to nighttime observing?

3. Why is it better for some purposes to use a medium size telescope on a mountain instead of a telescope on a spaceship at low orbit near the Earth?

4. What are the reasons why the Hubble Space Telescope is able to observe fainter objects than we can study from the ground?

5. The moon set in St.Petersburg (60œ North, 30œ East) yesterday just at midnight. In what region of the Earth will there be an opportunity to observe a total solar eclipse sometime next week?

6. Altair (a Aquila) has a parallax of p = 0".198, proper motion m = 0".658/year, radial velocity Vr = -26 km/s and visible brightness m = 0m.89. When and what would be the minimum distance of Altair to the Sun? Also find the brightness of Altair at that point.

7. Recently the Ten-meter Keck telescope began to operate on Mauna Kea (Hawaii), where the diameter of stellar images may be as small as 0".3. Can you evaluate the limiting stellar magnitude for visual observation with this telescope?

On the practical part problems were the following:

Paper with a drown circle and table of maximal elongations of Mercury and Venus had been done for participants.
1. The figure show a circle, that is the orbit of Earth. By using data from the table, draw orbits of Mercury and Venus.
2. Estimate radii of the orbits (in a.u.).

Table: Greatest Elongations of Mercury and Venus.
 Mercury: 1989-1990 Venus: 1983-1990 Date East West Date East West 8 Jan 89 19œ 15 Jun 83 45œ 18 Feb 89 26œ 4 Nov 83 47œ 30 Apr 89 21œ 21 Jan 85 47œ 18 Jun 89 23œ 12 Jun 85 46œ 28 Aug 89 27œ 26 Aug 86 46œ 10 Oct 89 18œ 15 Jan 87 47œ 22 Dec 89 20œ 2 Apr 88 46œ 1 Feb 90 25œ 22 Aug 88 46œ 13 Apr 90 20œ 8 Nov 89 47œ 31 May 90 25œ 30 Mar 90 46œ 11 Aug 90 27œ 24 Sep 90 18œ 5 Dec 90 21œ

As for observational part, its problem was non-competitional: