International Olympiad on Astronomy and Astrophysics

The International Olympiad on Astronomy and Astrophysics (IOAA) is a global competition for secondary school students. It features multiple components such as theory, data analysis, and observation rounds. This archive contains publicly shared problem and solution PDFs from past editions listed by IOAA.

2025 Mumbai, India
Data Analysis
Data Analysis Problems Data Analysis Solutions Data Analysis Answer Sheet
Problem D1 (90 pts)
30 Years of Exoplanets Data Analysis
Problem D2 (60 pts)
Predicting arrival times of coronal mass ejections on Earth Data Analysis
Theory
Theory Problems Theory Solutions Theory Answer Sheet
Problem T1 (10 pts)
Daksha Mission Theory
Problem T2 (10 pts)
Makar-Sankranti Theory
Problem T3 (15 pts)
Gravitational Waves Theory
Problem T4 (20 pts)
Balmer Decrement Theory
Problem T5 (20 pts)
Quasars Theory
Problem T6 (20 pts)
Galactic Rotation Theory
Problem T7 (20 pts)
Neutron Star Binary Theory
Problem T8 (20 pts)
Shadow of a black hole Theory
Problem T9 (20 pts)
Atmospheric Seeing Theory
Problem T10 (35 pts)
Big Bang Nucleosynthesis Theory
Problem T11 (50 pts)
Stars through graphs Theory
Problem T12 (20 pts)
Hawking Radiation from Black Holes Theory
Observation
Map OM01 Problems Map OM01 Solutions Map OM02 Problems Map OM02 Solutions Map OP01 Problems Map OP01 Solutions Map OP02 Problems Map OP02 Solutions Map OT01 Problems Map OT01 Solutions Observation Answer Sheet Answer SheetSky Map Problems Sky Map Solutions Sky Map Part 2 Problems Telescope Problems Telescope Solutions Telescope Part 2 Problems Planetarium Problems Planetarium Solutions Planetarium Answer SheetPlanetarium Part 2 Problems
Problem O3 (20 pts)
Map OM01 Map OM01
Problem O4 (20 pts)
Map OM02 Map OM02
Problem O5 (20 pts)
Map OP01 Map OP01
Problem O6 (20 pts)
Map OP02 Map OP02
Problem O7 (20 pts)
Map OT01 Map OT01
Problem O8 (20 pts)
Observation Observation
Problem O9 (20 pts)
Sky Map Sky Map
Problem O10 (20 pts)
Sky Map Part 2 Sky Map Part 2
Problem O11 (20 pts)
Telescope Telescope
Problem O12 (20 pts)
Telescope Part 2 Telescope Part 2
Problem P13 (20 pts)
Planetarium Planetarium
Problem P14 (20 pts)
Planetarium Part 2 Planetarium Part 2
General
Group Competition Problems Group Competition Solutions Group Competition Answer SheetGroup Competition Part 2 Problems
Problem G1 (150 pts)
Uncovering Galactic dark matter using a radio telescope Group Competition
Problem G16 (20 pts)
Group Competition Part 2 Group Competition Part 2
2024 Rio de Janeiro, Brazil
Data Analysis
Data Analysis Problems Data Analysis Solutions Data Analysis Grading Scheme
Problem D1 (75 pts)
Photometric comparison of surveys Data Analysis
Problem D2 (75 pts)
Shapley Hypothesis Data Analysis
Theory
Theory Problems Theory Solutions Theory Grading Scheme
Problem T1 (10 pts)
Sundial Theory
Problem T2 (10 pts)
Galaxy Cluster Theory
Problem T3 (10 pts)
Asteroid Theory
Problem T4 (10 pts)
White Dwarf Theory
Problem T5 (10 pts)
CMB Theory
Problem T6 (20 pts)
Cluster Photography Theory
Problem T7 (20 pts)
Castaway Theory
Problem T8 (25 pts)
Binary Hardening Theory
Problem T9 (35 pts)
Physics of Accretion Theory
Problem T10 (75 pts)
Greatest Eclipse Theory
Problem T11 (75 pts)
Ground Tracks Theory
Observation
Observation Problems Observation Grading Scheme Planetarium Problems Planetarium Solutions
Problem O1 (18 pts)
Stars within 8° of alpha Corvi (magnitude 4-6) Observation
Problem O2 (16 pts)
Alt-az sky chart orientation and great-circle markings Observation
Problem O3 (11 pts)
Meridian-transit and setting times from star chart Observation
Problem O4 (15 pts)
First stage: Pointing & Measurement Observation
Problem O5 (15 pts)
Second stage: Calculation and Identification Observation
Problem P1 (10 pts)
Problem 1 Planetarium
Problem P2 (10 pts)
Problem 2 Planetarium
2023 Katowice, Poland
Data Analysis
Data Analysis Solutions
Problem D1 (50 pts)
Distance to the Large Magellanic Cloud Data Analysis
Problem D2 (75 pts)
Isolated black hole Data Analysis
Theory
Theory Solutions Theory Solutions Theory Solutions
Problem T6 (13 pts)
Bolometer Theory
Problem T7 (20 pts)
Libration Theory
Problem T8 (20 pts)
Neutrinos Theory
Problem T9 (20 pts)
Second eclipse Theory
Problem T10 (25 pts)
Aldebaran Theory
Problem T11 (30 pts)
X-ray emission from galaxy clusters Theory Long
Problem T12 (40 pts)
DART Theory Long
Problem T13 (45 pts)
LISA Theory Long
Problem T1 (5 pts)
Neptune Theory Short
Problem T2 (5 pts)
Magnetic field Theory Short
Problem T3 (5 pts)
Microlensing Theory Short
Problem T4 (10 pts)
Europa Theory Short
Problem T5 (12 pts)
Dark Energy Theory Short
Observation
Observation Solutions Planetarium Solutions
Problem O1 (15 pts)
Asteroid occultation Observation
Problem O2 (15 pts)
Starlink Observation
Problem O3 (10 pts)
Planetary Moons Observation
Problem O4 (10 pts)
Supernova Observation
Problem P1 (20 pts)
Knowledge of the sky Planetarium
Problem P2 (20 pts)
Retrograde Mars Planetarium
Problem P3 (35 pts)
TRAPPIST-1 Planetarium
General
Group Competition Problems
Problem G1 (20 pts)
Multi-task team challenge (crossword, Arecibo message, Mars loop, astrolabe, Saros) Group Competition
2022 Kutaisi, Georgia
Data Analysis
Data Analysis Problems
Problem D1 (45 pts)
Gravitational wave astronomy Data Analysis
Problem D2 (105 pts)
Galactic Surveys Data Analysis
Theory
Theory Problems
Problem T1 (10 pts)
Planck's units Theory
Problem T2 (10 pts)
Circumbinary planet Theory
Problem T3 (10 pts)
Expanding ring nebula Theory
Problem T4 (10 pts)
Journey Between Galaxies Theory
Problem T5 (10 pts)
Flaring protoplanetary disk Theory
Problem T6 (20 pts)
Photometry of Binary stars Theory
Problem T7 (20 pts)
Georgia to Georgia Theory
Problem T8 (20 pts)
Ring of a planet Theory
Problem T9 (20 pts)
Solar Retrograde Motion on Mercury Theory
Problem T10 (20 pts)
Accretion Theory
Problem T11 (50 pts)
Dyson Sphere Theory
Problem T12 (50 pts)
Co-orbital satellites Theory
Problem T13 (50 pts)
Relativistic Beaming Theory
Observation
Observation Problems Observation Day Problems Observation Night Problems
Problem OA1 (15 pts)
Object identification with telescopes Observation
Problem OA2 (15 pts)
Telescope field of view Observation
Problem OA3 (6 pts)
Telescope focal length Observation
Problem OA4 (14 pts)
Binary star angle measurement Observation
Problem OD1 (9 pts)
Reflector type identification Observation Day
Problem OD2 (21 pts)
Equatorial constellations and ecliptic Observation Day
Problem OD3 (20 pts)
Messier objects and constellations Observation Day
Problem OD4 (30 pts)
Additional and missing stars Observation Day
Problem OD5 (5 pts)
Time interval from sky figures Observation Day
Problem ON1 (15 pts)
Object sequence identification Observation Night
Problem ON2 (15 pts)
Telescope field of view Observation Night
Problem ON3 (20 pts)
Albireo binary angle Observation Night
Problem ON4 (10 pts)
Telescope focal length Observation Night
2021 Bogota, Colombia
Data Analysis
Data Analysis 1 Problems Data Analysis 1 Solutions Data Analysis 2 Problems Data Analysis 2 Solutions
Problem D1 (75 pts)
Scaling Relations Data Analysis 1
Problem D2 (75 pts)
Stars and Exoplanets Data Analysis 2
Theory
Theory Problems Theory Solutions
Problem T1 (5 pts)
LIGO Theory
Problem T2 (10 pts)
Temperature of the Earth Theory
Problem T3 (10 pts)
Mars Theory
Problem T4 (10 pts)
ALMA - Calculating photons Theory
Problem T5 (10 pts)
Under pressure Theory
Problem T6 (12 pts)
Macondo and Melquiades Theory
Problem T7 (13 pts)
Menkalinan (Beta Aurigae) Theory
Problem T8 (15 pts)
IOAA Logo Theory
Problem T9 (15 pts)
Pluto Satellites Theory
Problem T10 (15 pts)
Terrestrial Transit Theory
Problem T11 (15 pts)
Minimum velocity of a projectile Theory
Problem T12 (15 pts)
Hodograph Theory
Problem T13 (15 pts)
Lucy: The First Mission to the Trojan Asteroids Theory
Problem T14 (35 pts)
Formation of the Venus-2 Theory
Observation
Observation Solar Physics Problems Observation Solar Physics Solutions Planetarium Problems Planetarium Solutions
Problem O1 (75 pts)
The Solar Slap Observation Solar Physics
Problem P1 (75 pts)
Simulated Sky Planetarium
Team/Group
Team/Group Competition Problems Team/Group Competition Solutions
Problem G1 (115 pts)
Group Radio Astronomy Team/Group Competition
2020 Estonia
Data Analysis
Data Analysis Problems Data Analysis Solutions Problems
Problem D1 (15 pts)
AGN Data Analysis
Problem D2 (50 pts)
Minor Planet Data Analysis
Problem D3 (55 pts)
Hypervelocity Stars Data Analysis
Theory
Theory Problems Theory Solutions Problems
Problem T1 (10 pts)
Astrophotography Theory
Problem T2 (10 pts)
Flat Earth Theory
Problem T3 (10 pts)
Mirror Theory
Problem T4 (20 pts)
Light Curves Theory
Problem T5 (20 pts)
HII region Theory
Problem T6 (20 pts)
Occultation of an X-ray Source Theory
Problem T7 (30 pts)
Radiant of a Meteor Shower Theory
Problem T8 (30 pts)
Jupiter's Great Red Spot Theory
Observation
Observation Problems
Problem O1 (15 pts)
Comets in the Sky Observation
Problem O2 (10 pts)
Neowise with MAGIC Observation
Problem O3 (40 pts)
All Sky Observation
Problem O4 (15 pts)
Sky Map Observation
General
Problem Q1 (20 pts)
Student Guide and Materials Student User With Screenshots
2019 Keszthely, Hungary
Data Analysis
Data Analysis Problems Data Analysis Solutions Problems Data Analysis Answer Sheet Problems
Problem D1 (60 pts)
Photometry and spectroscopy of Nova Del 2013 Data Analysis
Problem D2 (90 pts)
Triply eclipsing hierarchical triple stellar system Data Analysis
Theory
Theory Problems Theory Solutions Problems Theory Answer Sheet Problems
Problem T1 (10 pts)
Famous astronomical events Theory
Problem T2 (10 pts)
Deflection of radio photons in the gravitational field of solar system bodies Theory
Problem T3 (10 pts)
The supermassive black hole in the centre of Milky Way Galaxy and M87 Theory
Problem T4 (10 pts)
Improving a common reflecting telescope Theory
Problem T5 (10 pts)
Cosmic Microwave Background Oven Theory
Problem T6 (20 pts)
The height of the chimney of Tiszaujvaros power plant Theory
Problem T7 (20 pts)
Effect of sunspots on solar irradiance Theory
Problem T8 (20 pts)
Amplitude variation of RR Lyrae stars Theory
Problem T9 (20 pts)
Distance of the Lagrangian point L2 of the Earth-Moon system Theory
Problem T10 (20 pts)
South to East to North Theory
Problem T11 (25 pts)
Identification of light curves of selected variable star types Theory
Problem T12 (25 pts)
Distance to a Near-Earth Asteroid Theory
Problem T13 (40 pts)
Distance to the Coma galaxy cluster Theory
Problem T14 (60 pts)
Photographing a nanosatellite Theory
Observation
Observation Problems Observation Solutions Problems Planetarium Problems Planetarium Solutions Problems
Problem O1 (50 pts)
Telescope observational round (Saturn, M57, AF Cyg, naked-eye photometry) Observation
Problem P1 (20 pts)
Sky above Keszthely at midnight Planetarium
Problem P2 (20 pts)
Determining observing site from projected sky Planetarium
Problem P3 (20 pts)
Observing from the Moon during an Earth eclipse Planetarium
2018 Beijing, China
Data Analysis
Data Analysis Problems Data Analysis Solutions Problems
Problem D1 (20 pts)
Dust and Young Stars in Star-forming Galaxies Data Analysis
Problem D2 (20 pts)
Compact Object in a Binary System Data Analysis
Theory
Theory Problems Theory Solutions Problems
Problem T1 (10 pts)
Super Luminal Galaxies Theory
Problem T2 (10 pts)
Distance Theory
Problem T3 (10 pts)
Atmospheric Refraction Theory
Problem T4 (10 pts)
Height of a Hill Theory
Problem T5 (10 pts)
Sidereal Time Theory
Problem T6 (25 pts)
Observe the Sun with FAST Theory
Problem T7 (25 pts)
Sunspot Theory
Problem T8 (25 pts)
A Possible Dark Matter Deficient Galaxy Theory
Problem T9 (25 pts)
Radio Galaxy Theory
Problem T10 (75 pts)
Vega and Altair Theory
Problem T11 (75 pts)
Thermal History of the Universe Theory
Observation
Observation Day Problems Observation Night Problems
Problem O1 (40 pts)
Missing stars and planet on Yanqing all-sky chart Observation Day
Problem O2 (20 pts)
Date of Jupiter opposition from ecliptic chart Observation Day
Problem O3 (20 pts)
Mean solar time from equatorial star chart Observation Day
Problem O4 (20 pts)
Messier object identification from photos Observation Day
Problem O5 (10 pts)
Telescope field-of-view estimation Observation Night
Problem O6 (40 pts)
Identify text on observed LED screens Observation Night
2017 Phuket, Thailand
Data Analysis
Data Analysis Problems Data Analysis Solutions Problems
Problem D1 (75 pts)
Calibrating distance ladder to the LMC Data Analysis
Problem D2 (75 pts)
The search for dark matter Data Analysis
Theory
Theory Problems Theory Solutions Problems
Problem T1 (10 pts)
The Large Magellanic Cloud in Phuket Theory
Problem T2 (10 pts)
Earth's Transit Zone Theory
Problem T3 (10 pts)
The Milky Way's Distant Outer Arm Theory
Problem T4 (10 pts)
21-cm HI galaxy survey Theory
Problem T5 (10 pts)
A Synchronous Satellite Theory
Problem T6 (15 pts)
Supernova 1987A Theory
Problem T7 (20 pts)
Life on Other Planets Theory
Problem T8 (20 pts)
The Star of Bethlehem Theory
Problem T9 (20 pts)
Galactic Outflow Theory
Problem T10 (25 pts)
GOTO Theory
Problem T11 (50 pts)
Mass of the Local Group Theory
Problem T12 (40 pts)
Shipwreck Theory
Problem T13 (60 pts)
Exomoon Theory
Observation
Observation Day Problems Observation Night Problems
Problem P1 (20 pts)
Naked eye observation from real sky with panoramic 360-degrees image Observation Day
Problem P2 (20 pts)
Planet observation with real sky in panoramic 360-degrees image Observation Day
Problem P3 (20 pts)
Analemma on another planet Observation Day
Problem P4 (20 pts)
Exposure time from a Photograph Observation Day
Problem P5 (20 pts)
Find True North from Moon shadow Observation Day
Problem P6 (20 pts)
Find Latitude from Equatorial Mount Observation Day
Problem P7 (20 pts)
Precision Polar Alignment with Equatorial Mount Observation Day
Problem N1 (20 pts)
Observation with Equatorial Mount Telescope Observation Night
Problem N2 (20 pts)
Observation with Dobsonian Telescope Observation Night
2016 Bhubaneswar, India
Data Analysis
Data Analysis Problems Data Analysis Solutions Problems
Problem D1 (50 pts)
Binary Pulsar Data Analysis
Problem D2 (50 pts)
Distance to the Moon Data Analysis
Problem D3 (50 pts)
Type IA Supernovae Data Analysis
Theory
Theory Problems Theory Solutions Problems
Problem T1 (10 pts)
True or False Theory
Problem T2 (10 pts)
Gases on Titan Theory
Problem T3 (10 pts)
Early Universe Theory
Problem T4 (10 pts)
Shadows Theory
Problem T5 (10 pts)
GMRT beam transit Theory
Problem T6 (20 pts)
Cepheid Pulsations Theory
Problem T7 (20 pts)
Telescope optics Theory
Problem T8 (20 pts)
U-Band photometry Theory
Problem T9 (20 pts)
Mars Orbiter Mission Theory
Problem T10 (20 pts)
Gravitational Lensing Telescope Theory
Problem T11 (50 pts)
Gravitational Waves Theory
Problem T12 (50 pts)
AstroSat Theory
Observation
Observation Problems
Problem OT1 (10 pts)
Deep-sky object identification at preset telescope pointing Observation
Problem OT2 (20 pts)
M45 pointing and brightness ordering Observation
Problem OT3 (20 pts)
Mare Serenitatis diameter from drift Observation
Problem OP1 (40 pts)
Historical supernovae mapping on projected skies Observation
Problem OP2 (10 pts)
Celestial-pole identification on another planet's sky Observation
Problem OM1 (20 pts)
Star identification on map Observation
Problem OM2 (15 pts)
Galaxy location marking Observation
Problem OM3 (5 pts)
Draw ecliptic Observation
Problem OM4 (5 pts)
Autumnal equinox position Observation
Problem OM5 (5 pts)
Local meridian on winter solstice Observation
Team/Group
Team/Group Competition Problems
Problem G1 (20 pts)
Gravitational slingshot with Voyager-2 and Jupiter Team/Group Competition
2015 Magelang, Indonesia
Data Analysis
Data Analysis Problems Data Analysis Solutions Problems
Problem D1 (20 pts)
Photometry and radial velocity of Cepheid HV2257 Data Analysis
Problem D2 (20 pts)
Extinction law and distance estimate to IC 342 Data Analysis
Theory
Long Problems Long Solutions Problems Short Problems Short Solutions Problems
Problem T1 (20 pts)
Moon orbit in a plane perpendicular to the observer horizon Long
Problem T2 (20 pts)
Binary stars A and B and line-of-sight velocity constraints Long
Problem T3 (20 pts)
Thermodynamics of a static spherical star Long
Problem T4 (20 pts)
Resonant orbits in the Gliese 876 exoplanet system Short
Problem T5 (20 pts)
Planet mean density from satellite and Moon orbital data Short
Problem T6 (20 pts)
Diameter of asteroid 1285 Julietta from occultation Short
Problem T7 (20 pts)
Maximum resolvable distance of a supermassive black hole Short
Problem T8 (20 pts)
Orbital eccentricity from angular motion measurements Short
Problem T9 (20 pts)
Zenith atmospheric optical depth from calibrator attenuation Short
Problem T10 (20 pts)
Galaxy cluster density from escape velocity Short
Problem T11 (20 pts)
Brightness temperature of a short radio burst Short
Problem T12 (20 pts)
Venus radio flux density at closest approach Short
Problem T13 (20 pts)
Molecular hydrogen rotational excitation frequency Short
Problem T14 (20 pts)
Total mass from inverse-r density profile and escape velocity Short
Problem T15 (20 pts)
Travel time of a 1 GeV proton from Sun to Earth Short
Problem T16 (20 pts)
Average tidal heating power on Io Short
Problem T17 (20 pts)
Mean line-of-sight distance to a star in a static universe Short
Problem T18 (20 pts)
Southernmost latitude on the Lima-Yogyakarta great-circle route Short
Team/Group
Team/Group Competition Problems Team/Group Competition Solutions Problems
Problem G1 (20 pts)
Borobudur temple astronomical alignment Team/Group Competition
Problem G1 (20 pts)
Borobudur temple astronomical alignment - solutions Team/Group Competition Part 2
General
Table Of Constants Problems
Problem Q1 (20 pts)
Problem 1 Table Of Constants
2014 Suceava and Gura Humorului, Romania
Data Analysis
Data Analysis Problems
Problem D1 (20 pts)
Black Hole in Milky Way Data Analysis
Problem D2 (20 pts)
Thermodynamic Test Data Analysis
Problem D3 (20 pts)
IOAA Observer on an Extrasolar Planet Data Analysis
Theory
Long Problems Long Solutions Problems Short Solutions Solutions
Problem T1 (20 pts)
Eagles on the Caraiman Cross Long
Problem T2 (20 pts)
From Romania to Antipod with a ballistic messenger Long
Problem T3 (20 pts)
Lagrange Points Short Problemandsolution
Problem T4 (20 pts)
Sun gravitational catastrophe Short Problemandsolution
Problem T5 (20 pts)
Cosmic radiation Short Problemandsolution
Problem T6 (20 pts)
The Astronaut Saved by Ice from a Can Short Problemandsolution
Problem T7 (20 pts)
The lifetime of a main-sequence star Short Problemandsolution
Problem T8 (20 pts)
The effective temperature of a star Short Problemandsolution
Problem T9 (20 pts)
Pressure of light Short Problemandsolution
Problem T10 (20 pts)
Space-ship orbiting the Sun Short Problemandsolution
Problem T11 (20 pts)
The Vega star in the mirror Short Problemandsolution
Problem T12 (20 pts)
Stars with Romanian names Short Problemandsolution
Problem T13 (20 pts)
Apparent magnitude of the Moon Short Problemandsolution
Problem T14 (20 pts)
Absolute magnitude of a cepheid Short Problemandsolution
Observation
Observation Problems Planetarium Solutions Problems Planetarium Problems Problems
Problem O1 (20 pts)
Outdoor telescope tasks (meridian, pointing, and coordinate estimates) Observation
Problem P1 (20 pts)
Arc identification and sidereal-time/month estimate in dome Planetarium
Problem P2 (20 pts)
Messier object type and constellation identification in dome Planetarium
Problem P3 (20 pts)
Stellar type and constellation identification in dome Planetarium
Problem P1 (20 pts)
Sky-map construction (horizon, major circles, planets, and bright stars) Planetarium Part 2
Problem P2 (20 pts)
Sky-map constellation/object plotting and sidereal-coordinate estimates Planetarium Part 2
Team/Group
Team/Group Competition Problems Team/Group Competition Solutions Problems
Problem G1 (20 pts)
Defending the Earth from asteroid 2013 UX11 Team/Group Competition
Problem G1 (20 pts)
Defending the Earth from asteroid 2013 UX11 - solutions Team/Group Competition Part 2
2013 Volos, Greece
Data Analysis
Data Analysis Problems
Problem D1 (20 pts)
Focal length from Ursa Major image scale Data Analysis
Problem D2 (20 pts)
Solar rotation from sunspot tracking Data Analysis
Problem D3 (20 pts)
Hyades field photometry Data Analysis
Problem D4 (20 pts)
Hyades distance via moving-cluster method Data Analysis
Theory
Long Solutions Problems Short Solutions Problems
Problem T1 (20 pts)
Matter density and galaxy escape in an expanding universe Long And
Problem T2 (20 pts)
Orbit of asteroid Seneca from signal delay Long And
Problem T3 (20 pts)
Virial mass of a galaxy cluster Long And
Problem T4 (20 pts)
Mean Earth temperature with albedo Short And
Problem T5 (20 pts)
Minimum telescope diameter to resolve hot Jupiter Short And
Problem T6 (20 pts)
Main-sequence lifetime scaling with mass Short And
Problem T7 (20 pts)
Cepheid distance from PL relation Short And
Problem T8 (20 pts)
Hubble constant from H-alpha redshift Short And
Problem T9 (20 pts)
Distance luminosity and radius of a star Short And
Problem T10 (20 pts)
Luminosity classification from parallax and temperature Short And
Problem T11 (20 pts)
Apparent magnitudes of an unresolved binary Short And
Problem T12 (20 pts)
Equatorial coordinates from altitude and azimuth Short And
Problem T13 (20 pts)
Sgr A* black hole mass from stellar orbit Short And
Problem T14 (20 pts)
Maximum Full Moon altitude from Thessaloniki Short And
Problem T15 (20 pts)
Radius of Sirius B from magnitude difference Short And
Problem T16 (20 pts)
Optical depth of fog from Sun and Full Moon magnitudes Short And
Problem T17 (20 pts)
Hour angle and zenith angle of Vega Short And
Problem T18 (20 pts)
Galaxy recession velocities from redshift Short And
Observation
Observation Day Problems Observation Night Problems
Problem O1 (20 pts)
Noon equinox Sun-based telescope alignment Observation Day
Problem O1 (20 pts)
Telescope field-of-view from stellar drift timing Observation Night
Problem O2 (20 pts)
Locate M27 from gamma Sagitta without setting-circle reading Observation Night
Problem O3 (20 pts)
Spring-equinox daytime equatorial-mount alignment using Sun Observation Night
Team/Group
Team/Group Competition Problems Team/Group Competition Part 2 Problems
Problem G1 (20 pts)
Team quiz card (A-M astronomy puzzle sheets) Team/Group Competition
Problem G1 (20 pts)
Team quiz card (A-M astronomy puzzle sheets) - answer key Team/Group Competition Part 2
2011 Krakow - Katowice - Chorzow, Poland
Data Analysis
Data Analysis Problems
Problem D1 (20 pts)
Analysis of times of minima (V1107 Cas) Data Analysis
Problem D2 (20 pts)
Weighing a galaxy (NGC 7083 rotation curve) Data Analysis
Theory
Long Problems Short Problems
Problem T1 (20 pts)
HD209458 transit and host-star parameters Long
Problem T2 (20 pts)
Absolute magnitude of an elliptical galaxy at z = 0.500 Long
Problem T3 (20 pts)
Are two nearby solar-mass stars gravitationally bound? Long
Problem T1 (20 pts)
Oort-cloud comet travel time to inner Solar System Short
Problem T2 (20 pts)
Number of stars in a globular cluster from escape speed Short
Problem T3 (20 pts)
Voyager orbit type and apparent magnitude of the Sun Short
Problem T4 (20 pts)
Visibility duration of Phobos from Martian equator Short
Problem T5 (20 pts)
Equivalent radio telescope diameter at lambda = 1 cm Short
Problem T6 (20 pts)
Days per year 600 Myr ago from tidal torque Short
Problem T7 (20 pts)
Orbit outcomes after impulsive velocity change Short
Problem T8 (20 pts)
Dust-grain size at 1 AU from radiation-pressure balance Short
Problem T9 (20 pts)
Sky fraction obscured by stars in a galaxy field Short
Problem T10 (20 pts)
Minimum proton energy to penetrate magnetosphere Short
Problem T11 (20 pts)
Star-formation redshift from galaxy age at z = 6.03 Short
Problem T12 (20 pts)
Precession visibility of Sirius and Canopus from Krakow Short
Problem T13 (20 pts)
Galactic equator equation in horizontal coordinates Short
Problem T14 (20 pts)
Solar-neutrino flux at Earth Short
Problem T15 (20 pts)
CMB temperature-redshift relation and value at z ~ 10 Short
Observation
Observation Problems Observation Night Problems
Problem O1 (20 pts)
Planetarium round (Earth and Mars sky tasks) Observation
Problem O1 (20 pts)
Night round: Little Dolphin and declination determination Observation Night
Team/Group
Team/Group Competition Problems
Problem G1 (20 pts)
Multi-part group challenge (constellations, optics, eclipsing binary, nocturnal clock) Team/Group Competition
2010 Beijing, China
Data Analysis
Data Analysis Problems Data Analysis Solutions
Problem D1 (35 pts)
CCD image (35 points) Data Analysis
Problem D2 (35 pts)
Light curves of stars (35 points) Data Analysis
Theory
Long Solutions Solutions Short Solutions Solutions
Problem T1 (20 pts)
Parabolic Earth-to-Mars transfer geometry Long And
Problem T2 (20 pts)
Korribian Taris system dynamics Long And
Problem T3 (20 pts)
Combined magnitude of a binary system Short And
Problem T4 (20 pts)
Schwarzschild radius for a solar-mass object Short And
Problem T5 (20 pts)
QSO distance from redshift z = 0.20 Short And
Problem T6 (20 pts)
Binary component masses from orbit and angular separations Short And
Problem T7 (20 pts)
Maximum solar lifetime from mass-energy conversion Short And
Problem T8 (20 pts)
Can an astronaut walk around a small asteroid? Short And
Problem T9 (20 pts)
Maximum transit depth of an Earth-like exoplanet Short And
Problem T10 (20 pts)
Resolving Sgr A* event horizon with Earth-sized baseline Short And
Problem T11 (20 pts)
Photon rate from an I = 22 star on an 8 m telescope Short And
Problem T12 (20 pts)
Exponential vertical density drop in Galactic disc Short And
Problem T13 (20 pts)
Date of Mars great opposition in 2018 Short And
Problem T14 (20 pts)
Radius ratio from magnitude and temperature differences Short And
Problem T15 (20 pts)
Solar photosphere temperature from naked-eye color Short And
Problem T16 (20 pts)
Fourth contact time of a Venus transit Short And
Problem T17 (20 pts)
Annular-to-total solar eclipse occurrence ratio Short And
Observation
Observation Problems
Problem O1 (20 pts)
Telescope tests and planetarium sky-identification tasks Observation
2009 Tehran, Iran
Data Analysis
Data Analysis Problems Data Analysis Solutions Data Analysis 2 Problems
Problem D1 (60 pts)
CCD Image Processing (60 points) Data Analysis
Problem D2 (20 pts)
Venus Data Analysis
Problem D1 (20 pts)
CCD Image Processing data table Data Analysis 2
Theory
Long Problems Long Solutions Short Problems Short Solutions
Problem T1 (45 pts)
High Altitude Projectile Long
Problem T2 (45 pts)
Apparent number density of stars in the Galaxy Long
Problem T3 (20 pts)
Mean mass density of a supermassive black hole Short
Problem T4 (20 pts)
Photon rate at the eye from a G2V star Short
Problem T5 (20 pts)
Escape-by-jump planet radius estimate Short
Problem T6 (20 pts)
South-side window overhang from solar geometry Short
Problem T7 (20 pts)
Damavand Mountain and Caspian horizon geometry Short
Problem T8 (20 pts)
Escape velocity in a uniform protostar cloud Short
Problem T9 (20 pts)
Eyepiece field of view measurement Short
Problem T10 (20 pts)
Mass estimate of a globular cluster Short
Problem T11 (20 pts)
Galactic longitude and radial velocity relation Short
Problem T12 (20 pts)
Main-sequence star average density estimate Short
Problem T13 (20 pts)
Number density of relic neutrinos Short
Problem T14 (20 pts)
Increase in Earth orbit radius from solar mass loss Short
Problem T15 (20 pts)
Copernican-era astronomical inference Short
Problem T16 (20 pts)
Equatorial satellite orbital geometry Short
Problem T17 (20 pts)
Equal-size eclipsing giant binary system Short
Observation
Observation Problems Observation Solutions
Problem O1 (20 pts)
Star mapping in Perseus/Andromeda and telescope coordinate measurements Observation
2008 Bandung, Indonesia
Data Analysis
Data Analysis Problems
Problem D1 (20 pts)
Virgo cluster weighted-distance estimate Data Analysis
Problem D2 (20 pts)
Masses in the visual binary Alpha Centauri A-B Data Analysis
Problem D3 (20 pts)
Meteorite ages from Rb-Sr isochrones Data Analysis
Theory
Long Problems Long Solutions Short Problems Short Solutions
Problem T1 (20 pts)
Eclipsing-binary masses and radii from light and radial-velocity curves Long
Problem T2 (20 pts)
UBV photometry with reddening to infer stellar properties Long
Problem T3 (20 pts)
CMB horizon problem and inflation-era size estimate Long
Problem T1 (20 pts)
Lunar parallax in right ascension from opposite longitudes Short
Problem T2 (20 pts)
Solar active-region area in msh from CCD image scale Short
Problem T3 (20 pts)
Minimum and maximum moonrise duration at Bosscha Short
Problem T4 (20 pts)
Helium-burning lifetime of a massive star Short
Problem T5 (20 pts)
Dark matter to dark energy ratio at CMB epoch Short
Problem T6 (20 pts)
Black-hole mass from HI line shift of orbiting gas cloud Short
Problem T7 (20 pts)
Visibility distance change from main sequence to giant branch Short
Problem T8 (20 pts)
Horizontal tidal acceleration at Earth's equator Short
Problem T9 (20 pts)
Earth's surface temperature with atmospheric transmittance Short
Problem T10 (20 pts)
Visual binary Mu Sco frame fit and position angle Short
Problem T11 (20 pts)
Distances and coverage in annular solar eclipse geometry Short
Problem T12 (20 pts)
Type Ia supernova distance and Hubble time Short
Problem T13 (20 pts)
Telescope angle extrema to a circular target boundary Short
Problem T14 (20 pts)
Potentially hazardous object mass and energy from u-p data Short
Problem T15 (20 pts)
NGC 2639 mass and luminosity from Tully-Fisher relation Short
Observation
Observation Problems
Problem O1 (20 pts)
Missing-star identification in Scorpio and Capricorn Observation
Problem O2 (20 pts)
Telescope/CCD star-field identification and limiting magnitude Observation
2007 Chiang Mai, Thailand
Data Analysis
Data Analysis Problems Data Analysis Solutions
Problem D1 (20 pts)
Galilean moons identification Data Analysis
Problem D2 (20 pts)
Moon age from June 2006 lunar photos Data Analysis
Problem D3 (20 pts)
Solar System objects from apparent-position table Data Analysis
Theory
Theory Problems Theory Solutions
Problem T1 (20 pts)
Sunrise time at 42.5 N on 21 December Theory
Problem T2 (20 pts)
Venus orbital radius from maximum elongation Theory
Problem T3 (20 pts)
Convert 183 solar days to sidereal days Theory
Problem T4 (20 pts)
Earth-Moon distance from lunar angular size Theory
Problem T5 (20 pts)
Minimum measurable stellar parallax at 100 pc Theory
Problem T6 (20 pts)
Comet orbital period from perihelion and aphelion Theory
Problem T7 (20 pts)
Comet areal velocity around the Sun Theory
Problem T8 (20 pts)
Peak-emission wavelength of a 4000 K star Theory
Problem T9 (20 pts)
Luminosity of a 7500 K star with radius 2.5 R_sun Theory
Problem T10 (20 pts)
Distance to a K-type main-sequence star from flux Theory
Problem T11 (20 pts)
Distance to a supernova as bright as the Sun Theory
Problem T12 (20 pts)
Gas-cloud radial velocity from HI 21 cm frequency shift Theory
Problem T13 (20 pts)
Naked-eye resolution of an 80 km lunar crater Theory
Problem T14 (20 pts)
Schwarzschild radius of the Sun Theory
Problem T15 (20 pts)
Flux ratio of m=6 star to m=-1.5 star Theory
Problem T16 (20 pts)
Equilibrium temperature and albedo of a planet Theory
Problem T17 (20 pts)
Gravitational lensing and Einstein ring properties Theory
Observation
Observation Problems Observation Solutions
Problem O1 (20 pts)
Celestial-pointer sky targeting tasks Observation
Problem O2 (20 pts)
Binocular observations of Hyades and M31 Observation