The International Olympiads on Astronomy and Astrophysics (IOAA) are competitions where teams of high-school students from around the world compete in a series of tests and are awarded medals based on their performance.  Started in 2007, more than 45 countries have participated in these olympiads. The competition comprises three rounds: theoretical problems, data analysis problems and night sky observation tests. This book presents problems from all the eight IOAAs held thus far. The problems are categorised according to the concepts involved and also graded according to the difficulty level. Solutions to all the problems are provided. Additional notes help make the solutions self-explanatory.

Aniket Sule is Academic Coordinator of the Indian Astronomy Olympiad Programme, Regional Coordinator (Asia-Pacific) of IOAA and Reader at the Homi Bhabha Centre for Science Education, Tata Institute of Fundamental Research, Mumbai.

Preface 

Acknowledgments 

Academic Committees of Previous IOAAs 

President´s Message 

A Note about the Problems 

Table of Constants 

1 Celestial Mechanics 

1.1 Theory 

1.2 Data Analysis 

2 Celestial Coordinate Systems 

2.1 Theory 

2.2 Data Analysis 

3 Geometric Astronomy and Time 

3.1 Theory 

3.2 Data Analysis 

4 Optics and Detectors 

4.1 Theory 

4.2 Data Analysis 

5 Physics of Stars and Planets 

5.1 Theory 

5.2 Data Analysis 

6 Stellar Observations 

6.1 Theory 

6.2 Data Analysis 

7 Binaries and Variables 

7.1 Theory 

7.2 Data Analysis 

8 Galactic Astrophysics 

8.1 Theory 

8.2 Data Analysis 

9 Extragalactic Astrophysics 

9.1 Theory 

9.2 Data Analysis 

10 Night Sky Observation 

10.1 General Night Sky 

10.2 Magnitudes and Angular Sizes 

10.3 Instrument Aided Observations 

10.4 Planetarium Based Questions 

11 Solutions: Celestial Mechanics 

11.1 Theory 

11.2 Data Analysis 

12 Solutions: Celestial Coordinate Systems 

12.1 Theory 

12.2 Data Analysis 

13 Solutions: Geometric Astronomy and Time 

13.1 Theory 

13.2 Data Analysis 

14 Solutions: Optics and Detectors 

14.1 Theory 

14.2 Data Analysis 

15 Solutions: Physics of Stars and Planets 

15.1 Theory 

15.2 Data Analysis 

16 Solutions: Stellar Observations 

16.1 Theory 

16.2 Data Analysis 

17 Solutions: Binaries and Variables 

17.1 Theory 

17.2 Data Analysis 

18 Solutions: Galactic Astrophysics 

18.1 Theory 

18.2 Data Analysis 

19 Solutions: Extragalactic Astrophysics 

19.1 Theory 

19.2 Data Analysis 

20 Solutions: Night Sky Observation 

20.1 General Night Sky 

20.2 Magnitudes and Angular Sizes 

20.3 Instrument Aided Observations 

20.4 Planetarium Based Questions 

Appendix: Syllabus of IOAA 

A.1 General Notes 

A.2 Theoretical Part 

A.2.1 Basic Astrophysics 

A.2.2 Coordinates and Times 

A.2.3 Solar System 

A.2.4 Stars 

A.2.5 Stellar Systems 

A.2.6 Cosmology 

A.2.7 Instrumentation and Space Technologies 

A. 3 Practical Part