IOAA International Olympiad on Astronomy & Astrophysics 2017 Theoretical Examination Question Paper

Name of the Organisation : International Olympiad on Astronomy and Astrophysics (IOAA)
Name of the Exam : International Olympiad on Astronomy and Astrophysics 2017
Document Type : Sample Question Paper
Website : https://ioaa2017.posn.or.th/ioaa_about.php
Download Question Paper :
Theory Questions : https://www.pdfquestion.in/uploads/22887-Theory.pdf
Theory Solutions : https://www.pdfquestion.in/uploads/22887-Solution.pdf

IOAA Olympiad on Astronomy & Astrophysics Question

** International Olympiad on Astronomy and Astrophysics (IOAA) is an annual event for highly performed high school students from all around the world.

Related : Amity International Olympiad Theoretical Science Sample Question Paper : www.pdfquestion.in/22883.html

** Established in Thailand 2006, it was initiated by five countries including Thailand, Indonesia, Iran, China and Poland with the aim to proliferate Astronomy among high school students, to foster friendship among young astronomers at international level so as to build cooperation in the field of Astronomy in the future among the young scholars.

Theoretical Examination

** The theoretical examination consisting of 15 short questions and 2 or 3 long questions, with 5 hours to solve. It counts as 50% of the mark.
** The theoretical examination lasts for 5 hours and is worth a total of 300 marks.

Instructions

1. The theoretical examination lasts for 5 hours and is worth a total of 300 marks.
2. Dedicated IOAA Summary Answer Sheets are provided for writing your answers. Enter the final answers into the appropriate boxes in the corresponding Summary Answer Sheet. On each Summary Answer Sheet, please fill in
** Student Code (Country Code and 1 digit)

3. There are Answer Sheets for carrying out detailed work/rough work. On each Answer Sheet, please fill in
** Student Code (Country Code and 1 digit)
** Question no.
** Page no. and total number of pages.

4. Start each problem on a separate Answer Sheet. Please write only on the printed side of the sheet. Do not use the reverse side. If you have written something on any sheet which you do not want to be evaluated, cross it out.

5. Use as many mathematical expressions as you think may help the evaluator to better understand your solutions. The evaluator may not understand your language. If it is necessary to explain something in words, please use short phrases (if possible in English).

6. You are not allowed to leave your work desk without permission. If you need any assistance (malfunctioning calculator, need to visit a restroom, need more Answer Sheets, etc.), please draw the attention of the proctor using the Help card.

7. The beginning and end of the examination will be indicated by a long sound signal. Additionally, there will be a buzzer sound, fifteen minutes before the end of the examination (before the final sound signal).

8. At the end of the examination you must stop writing immediately. Sort and put your sheets in separate stacks,
a) Stack 1: Summary Answer Sheets, Answer Sheets of part 1
b) Stack 2: Summary Answer Sheets, Answer Sheets of part 2
c) Stack 3: Summary Answer Sheets, Answer Sheets of part 3
d) Stack 4: question papers and paper sheets you do not want to be graded.

9. Wait at your table until your envelope is collected. Once all envelopes are collected, your student guide will escort you out of the examination room.

10. A list of constants and a table of the mark distribution for this exam are given on the next two pages.

Part 1 :
(T1) The Large Magellanic Cloud in Phuket [10 marks]
The coordinates of the Large Magellanic Cloud (LMC) are R.A. = 5h 24min and Dec = 70 00? ? . The latitude and longitude of Phuket are 7 53 N ? and 98 24 E ? , respectively. What is the date when the LMC culminates at 9pm as seen from Phuket in the same year? You may note that the Greenwich Sidereal Time, GST, at 00h UT 1st January is about 6h 43min, and Phuket is in the UT+7 time zone. [10]

(T2) Earth’s Transit Zone [10 marks]
Earth’s transit zone is an area where extrasolar observers (located far away from the Solar System) can detect the Earth transiting across the Sun. For observers on the Earth, this area is the projection of a band around the Earth’s ecliptic onto the celestial plane (light grey area in the left figure). Assume that the Earth has a circular orbit of 1 au.

a) Find the angular width of that part of the Earth’s transit zone in degrees, in which the extrasolar observers can detect Earth’s total transit (when the whole of the Earth’s disk passes in front of the Sun). [5]
b) Find the angular width of that part of the Earth’s transit zone in degrees, where the extrasolar observers can detect at least Earth’s grazing transit (when any part of the Earth’s disk passes in front of the Sun). [5]

(T3) The Milky Way’s Distant Outer Arm [10 marks]
In 2011, Dame and Thaddeus found a new part of the outer arm of the Milky Way by studying the CO line using the CfA 1.2m telescope. They found that the CO line was detected at galactic longitude ?13.25 (marked A in the figure) where it had a radial velocity of 20.9 km s-1 towards the Sun. Assume that the galactic rotation curve is flat beyond 5 kpc from the Galactic centre. The distance between the Sun and the Galactic centre is 8.5 kpc. The velocity of the Sun around the Galactic centre is 220 km s-1.
a) Find the distance from the start of the arm (point A) to the Galactic centre. [7]
b) Find the distance from the start of the arm (point A) to the Sun. [3]

(T4) 21-cm HI galaxy survey [10 marks]
A radio telescope is equipped with a receiver which can observe in a frequency range from 1.32 to 1.52 GHz. Its detection limit is 0.5 mJy per beam for a 1-minute integration time. In a galaxy survey, the luminosity of the HI spectral line of a typical target galaxy is 28 10 W with a linewidth of 1 MHz. For a large beam, the HI emitting region from a far-away galaxy can be approximated as a point source. The HI spin-flip spectral line has a rest-frame frequency of 1.42 GHz.
What is the highest redshift, z , of a typical HI galaxy that can be detected by a survey carried out with this radio telescope, using 1-minute integration time? You may assume in your calculation that the redshift is small and the non-relativistic approximation can be used. Note that 1 Jy = 10-26 W m-2 Hz-1. [10]

(T5) A Synchronous Satellite [10 marks]
A synchronous satellite is a satellite which orbits the Earth with its period exactly equal to the period of rotation of the Earth. The height of these satellites is 35786 km above the surface of the Earth. A satellite is put in an inclined synchronous orbit with an inclination of? ? 6.69? to the equatorial plane. Calculate the precise value of the maximum possible altitude of the satellite for an observer at latitude of ? ? 51.49?. Ignore the effect of refraction due to theEarth’s atmosphere. [10]