Astronomy Quiz

On which two quantities depends the apparent brightness of an object?

• On its distance to the observer

• On its altitude above the horizon

• On its height above the Equator

• On its intrinsic brightness

Define physically a black hole:

• It is a region of space with a high mass density

• It is a region of space with a large quantity of mass

• It is a region of space where the scape velocity is higher than the speed of light

• It is a region of space where the scape velocity is higher than the speed of sound

Identify three advantages of the equatorial coordinate system (based on the terrestrial Equator and a fixed point in the celestial sphere) with respect to the alt-azimuthal system (based on the horizon and the North cardinal point):

• The stars move in a fixed coordinate in the equatorial system

• The horizon depends on the observer

• The North cardinal point depends on the observer

• The coordinates of a given star are constant in the equatorial system

What is the origin of the seasons on Earth?

• The variable distance between Sun and Earth

• The inclination of the rotation axis of the Earth with respect to its orbital plane

• The inclination of the rotation axis of the Sun with respect to the orbital plane of Earth

• The varying levels of solar activity

Select one or more negative effects of the atmosphere on astronomical observations:

• Absorption

• Dispersion

• Refraction

• Distortion

Identify two reasons why large diameter telescopes are preferred in Astronomy:

• Because more light is gathered in that way

• Because the defects of the mirrors are averaged out

• Because the effects of diffraction are reduced

• Because the field of view of the telescope is larger

Why do stars have different colours?

• Because they are at different distances

• Because they have different sizes

• Because they have different chemical abundances

• Because they have different surface temperatures

What is the fundamental parameter that determines the evolution of a star?

• Its size

• Its temperature

• Its mass

• Its chemical abundances

Enumerate two observational evidences supporting the existence of dark matter:

• There are regions of space which do not emit light

• There is more gravitational mass in galaxies than the sum of the stars and gas that they contain

• There is more gravitational mass in clusters of galaxies than the sum of the galaxies and gas that they contain

• There are regions of space with matter which does not emit visible light

Enumerate two observational evidences supporting the Big Bang model:

• The expansion of the Universe

• The Cosmic X-ray Background

• The Cosmic Microwave Background

• The evolution of galaxies