IAAC Final Exam 2019 – Astronomy & Astrophysics Review

40 question-and-answer flashcards summarizing essential facts and definitions from the IAAC 2019 final-round multiple-choice exam.

Approximately how many Kelvin correspond to 25 °C?

About 300 K

Why can humans not breathe on the surface of Mars?

Its atmosphere is composed mostly of carbon-dioxide (CO₂).

What are the names of Mars’ two natural satellites?

Phobos and Deimos

Which planet hosts the Great Red Spot?

Jupiter

What is the approximate axial tilt of Earth relative to its orbital plane?

≈ 23.5 °

The Pleiades open cluster is famous for containing how many bright stars?

Seven

What is the second-closest star system to Earth after Alpha/Proxima Centauri?

Barnard’s Star

What wavelength range defines visible light?

Roughly 380 nm to 740 nm

Which bright, W-shaped constellation is easily seen in northern skies?

Cassiopeia

In astronomy, what does bolometric luminosity measure?

The total luminosity integrated over all wavelengths

Give the formula for escape velocity from a body of mass M and radius R.

v = √(2 G M / R)

What is the approximate orbital speed of the International Space Station?

≈ 28 000 km h⁻¹

What is the Sun’s surface (photospheric) temperature?

≈ 6000 K

Which Galilean moon orbits closest to Jupiter?

Io

Name the super-massive black hole at the center of the Milky Way.

Sagittarius A*

How far away is the Andromeda Galaxy (M31)?

≈ 2.5 million light-years

In what year did Galileo first use a telescope for astronomy?

1609

How is one parsec defined?

The distance at which 1 AU subtends an angle of 1 arcsecond

What is the famous nebula located in Orion, often photographed by NASA?

The Orion Nebula

Betelgeuse belongs to which constellation?

Orion

What does the term “ecliptic” describe?

The apparent annual path of the Sun across the sky

Approximately how long is Pluto’s orbital period?

About 250 years

The number of sunspots peaks every ___ years (solar cycle).

11

What is the Large Magellanic Cloud?

A dwarf galaxy orbiting the Milky Way

What is the name of the supercluster that contains the Milky Way?

Laniakea Supercluster

Why are Cepheid variable stars important?

Their period–luminosity relation allows measurement of extragalactic distances

What radiation leads to the slow evaporation of black holes?

Hawking radiation

Define a perfect black body in physics.

An ideal object that absorbs all incident electromagnetic radiation

What is the value of 1 astronomical unit (AU) in kilometres?

≈ 150 million km

Which radio telescope once had the world’s largest single parabolic dish?

The Arecibo Telescope (305 m)

Which of the following constellations is NOT on the Milky Way’s band?

Leo

In which direction does a comet’s tail point?

Away from the Sun

What is the correct sequence of element shells in an evolved massive star (outer to inner)?

H → He → C → O → Ne → Si → Fe

Dark energy was introduced primarily to explain what cosmic observation?

The accelerating expansion of the universe

Write the nuclear equation for the triple-alpha process.

³ ⁴He + ⁴He + ⁴He → ¹²C + γ

Which cosmic particle interacts the least with other matter?

Neutrinos (ν)

The term “Schwarzschild radius” refers to which objects?

Black holes

State the numerical value of Boltzmann’s constant.

k = 1.38 × 10⁻²³ m² kg s⁻² K⁻¹

What is characteristic of a type-Ia supernova?

It occurs in binary star systems (white dwarf accreting matter).

What central question is addressed by the Drake equation?

Whether technologically advanced extraterrestrial civilizations are likely to exist