Astro Quiz PDF

Question 1 Mark the element that is NOT part of World Geodetic System a. A parallel plane defined on the surface b. A gravitational equipotential surface c. A standard coordinate system d. A standard spheroidal reference surface Question 2 Two reference systems have the East-West axis in common a....

Question 1 Mark the element that is NOT part of World Geodetic System a. A parallel plane defined on the surface b. A gravitational equipotential surface c. A standard coordinate system d. A standard spheroidal reference surface Question 2 Two reference systems have the East-West axis in common a. Horizontal and Ecliptic systems b. Horizontal and Equatorial systems \ c. Equatorial and Ecliptic systems d. Galactic and Equatorial systems Question 3 Mark the correct definition of Vernal Point a. intersection between the Horizon and the Equator b. intersection between the Ecliptic and the Horizon c. intersection between the Equator and the Ecliptic d. intersection between the Local Meridian and the Horizon Question 4 Mark the correct definition of PARSEC a. distance at which Earth's radius subtends an angle of one arc minute b.distance at which one astronomical unit subtends an angle of one arc second c. distance travelled by the light in one year, in vacuum conditions d. displacement of the Sun in one century along its orbit around the Galaxy Question 5 Mark the WRONG sentence a.The motion of the Sun on the sky is not uniform due to Earth eccentricity b.The motion of the Sun on the Equator is not uniform because it moves on the Ecliptic c.The Mean Solar Time is equal to the Hour Angle of the Mean Equinox, plus 12 hours d.The Mean Sun moves at constant angular velocity on the equator, with period of one tropical year Question 6 Mark the WRONG definition among the proposed ones a. Draconic year: time between two consecutive passages of the Moon on the Vernal Point b. Solar Day: time between two consecutive passages of the Sun through the Local Meridian c. Sidereal Day: time between two consecutive passages of Vernal Point through the Local Meridian d. Tropical Year: time between two consecutive passages of the Sun on the Vernal Point Question 7 Mark the WRONG sentence regarding the formation of spectral lines a. Chemical elements absorb or emit at specific wavelengths, depending on their electronic structure b. Emission lines are formed when atoms in an excited state go back to the ground state c. Absorption lines are formed when photons from a cold source pass through a hotter one d. A continuous spectrum can be produced by heated-up material or hot gas at high pressure Question 8 Mark the correct sentence regarding the electromagnetic spectrum. a. The energy associated with a photon decreases with increasing wavelength.  b. The wavelength of a photon is equal & to its frequency multiplied by the speed of light c. A Gamma ray photon is less energetic than an UltraViolet photon d. The Visible range is the main component of the electromagnetic spectrum Question 9 Mark the WRONG sentence regarding the photometric color index of a star a. The color index is a good observational estimate for the effective temperature of the star b. The color index is not affected by the stellar radius or the distance of the star c. The color index is obtained by comparing the flux density ina two different wavelengths d. The color index can be computed as the differe in nce in magnitude between two stars Question 10 Mark the WRONG sentence regarding the measurement of radiation a. A source emitting radiation is isotropic if its intensity is independent of the angle b. The total intensity is obtained by integrating the specific density over a solid angle c. A radiation field is isotropic if the intensity is independent of direction d. The specific intensity emitted from a depends on its frequency and direction Question 11 Mark the WRONG sentence regarding different types of spectrographs a. Multi-Object spectrographs can take spectra of several objects in the focal plane at the same time b. Echelle spectrographs allow for extremely high resolution, but only for ground instruments c. Slit spectrographs can only be used for point-like sources and not for extended objects d Unit spectrographs split the image in several parts, a spectrum is obtained for each one Question 12 Mark the WRONG sentence regarding slit spectroscopy a.The dispersive element is parallel to a slit, placed on the focal plane of the telescope b. Spectrum can be regarded as an infinite number of monochromatic images of the entrance slit c. Increasing the width of the slit causes a degradation (reduction) of the spectral resolution d. It allows high spectral resolution but its complexity makes it not suitable for space telescopes Question 13 What is the percentage of the main components of the primordial solar nebula? a.Hydrogen and Helium 98% b. Hydrogen and Helium 88% c. Hydrogen and Helium 92% d.Hydrogen and Helium 75% Question 14 Main differences between and outer planets a. planets have higher than the outer planets b. planets have primitive atmospheres, outer planets have secondary atmospheres c. Outer planets atmosphere is primarily composed of CO2, planets atmosphere of H d. planets are made of rocks and metals, outer planets of gas (He,H) and ice Question 15 What is the main component of the Earth atmosphere? a. Oxygen b. Water c. Nitrogen d. Carbon dioxide Question 16 What does the depend on? a. The radius of the main planet times the cubic root of the ratio of the densities of the two bodies b. The ratio between the mass and the radius of the satellite approaching the planet c. The cubic root of the ratio between the mass of the planet and the radius of the satellite d. The distance between the two bodies times the square root of the mass of the planet times the mass of the satellite Question 17 What are the shepherd satellites? a. Small satellites orbiting among the rings of Saturn and also among the rings of other Giant planets b. Small objects orbiting in the Kuiper Belt c. Small objects orbiting in the Main Belt d. Small asteroids in the Jupiter's Lagrangian points L4 and L5 Question 18 How much bigger is the mass of Jupiter compared to that of the Earth? a. 280 times b. 200 times c. 348 times d. 317 times Question 19 What is the main component of the Jovian planets? a. Hydrocarbons b. Ammonia and Methane c. Methane d. Helium and Hydrogen Question 20 How does the cometary ion tail form? a. Interaction between neutral molecules and solar wind b. Interaction between cometary ions and solar wind c. Interaction between cometary dust and ions d. Interaction between cometary ions and solar radiation pressure Question 21 Which satellite in the Solar System has a thick atmosphere? a.Triton b. Europa c. Titan d. Ganymede Question 22 Mark the WRONG sentence regarding the Main Sequence phase a. In the colour-magnitude diagram, Main Sequence stars are randomly scattered all across the diagram b. Stars more massive than 120 solar masses are predicted to be unstable, although exceptions have been observed c. Objects with mass smaller than 0.08 solar masses are not massive enough to start Hydrogen fusion d. The energy to sustain the hydrostatic equilibrium of the star is provided by Hydrogen fusion in the core Question 23 Mark the WRONG sentence regarding the lifetime of a star radiating as the Sun a. By radiating its gravitational potential energy, a star could only survive a few millions of years b. Nuclear reactions keep a star in balance for billions of years only if all of its mass is converted to energy c. Without any internal pressure to counterbalance gravity, a star would collapse in about half an hour d. Chemical reactions or radioactivity are not efficient enough to justify the luminosity of the Sun Question 24 Mark the WRONG sentence regarding the Carbon burning phase and beyond in stellar evolution (massive stars) a. After Carbon ignition, the star goes through a series of alternating nuclear burning / core contraction cycles b. Carbon fusion in the core starts if the Carbon-Oxygen core has a mass greater than 1.06 solar masses c. Each nuclear burning phase is much quicker than the previous one, with Silicon-burning lasting only a few weeks d. Each nuclear burning phase converts the totality of the mass of the star in an element with higher atomic number Question 25 Mark the WRONG sentence regarding the nuclear fusion reactions in stars a. In the Sun 99% of the energy is produced by the proton-proton chain, and 91% by the ppl chain b. The proton-proton IlI chain, even CNOfi marginal, explains the very high energy neutrinos from the Sun c. The Carbon-Nitrogen-Oxygen cycle is predominant only for stars more massive than the Sun d. The CNO cycle causes a noticeable variation in the abundance of "metals" in the core of the star Question 26 Mark the WRONG sentence regarding white dwarfs a. Compression does not lead to heating and expansion as in regular stars: increasing the mass causes smaller radius b. The electron degeneracy pressure is independent of temperature, but it depends only on the density of matter c. Electron degeneracy pressure can support a white dwarf of any mass, regardless of its origin d. White dwarfs are mainly composed % of Carbon and Oxygen, with a thin Hydrogen or Helium atmosphere Question 27 Mark the WRONG sentence regarding black holes and compact objects a. The interaction between two compact objects, or a compact object and star, will cause emission of very energetic photons b. A black hole can be identified by observing the orbit of the material in the accretion disk or of the stars around it c. From the outside, we would see the local clock of someone falling into a black hole increasing its speed exponentially d. The merging of compact objects is so energetic that creates ripples in the space-time continuum, called gravitational waves Question 28 Mark the WRONG sentence regarding the rotation of the Sun a.Inside the convective zone, the angular velocity is similar to that of the surface. The radiative core rotates as a rigid body b. The transition zone between the radiative zone and the convective one is called tachocline c.The Sun rotates at the same angular velocity from its equator the poles, and it can be approximated to a rotating rigid body d. The rotational period of the Sun, at a given latitude, can be expressed as sidereal or synodic (slightly longer than synodic) Question 29 Mark the WRONG sentence regarding the atmosphere of the Sun a. The photosphere can be observed & using a telescope with an H-alpha filter, while the corona can be observed only during an eclipse b. The solar atmosphere is divided into the corona (300-500 km thick) and the photosphere (over 500 km). The chromosphere extends much further out c. The chromosphere is characterized by an inversion of the temperature gradient, increasing outward, and very small densities d.In the photosphere, the temperature rapidly increases inwards, from 4500 K to 8000 K. This is the origin of the limb darkening effect Question 30 Mark the WRONG sentence regarding the definition of planet/exoplanet a. A planet/exoplanet can orbit another planet or float free in space b. A planet/exoplanet has "cleared the neighbourhood" around its orbit c. A planet/exoplanet has sufficient mass to assume hydrostatic equilibrium a nearly round shape) d. A planet/exoplanet is in orbit around the Sun/star Question 30 Mark the WRONG sentence regarding the classification of exoplanet discoveries a. Object of Interest: a star showing a planet-like signal of unknown origin b. Validated planet: a candidate planet with a very small probability of being a false positive c. Confirmed planet: the planet has been detected or characterized using an independent technique d. Candidate planet: a planet selected by the International Astronomical Union as a possible Earth 2.0 Question 31 Mark the WRONG sentence regarding these properties of galaxies a. Galaxy formation theories can be divided into two main groups: "Hierarchical" and "Monolithic" b. Elliptical galaxies are mainly composed of old low-mass stars, sparse interstellar medium and minimal star formation c. It is nearly impossible for galaxies to collide or merge. Structural properties are preserved since their formation. d. The constant velocity of the gas in the outskirts of galaxies led to the discovery of dark matter Question 32 Mark the WRONG sentence regarding stellar clusters and association a. The Messier and NGC catalogues include a careful selection of open and globular clusters, with all possible constellations and asterisms cleaned out b. A Group of young stars, with a few tens of members, is called an association. It will dissolve very quickly, forming stellar streams and moving groups c. Open clusters can contain up to thousands of stars. They are more gravitationally bounded than associations and they will dissolve on longer timescales d. Stars in clusters formed from the same giant molecular cloud, have similar distance and kinematics, have roughly the same age and chemical abundances Question 33 Mark the WRONG sentence regarding the properties of galaxies a. Galaxies are not randomly distributed in space, but they aggregate in groups and cluster b. A Galaxy is a gravitationally bound system formed of stars, stellar remnants, dust, interstellar gas, and dark matter c. The Andromeda Galaxy would look much larger than the Moon if it was bright enough for our eye d. Small galaxies do exist isolated from other galaxies, and they never orbit larger galaxies Question 34 Mark the WRONG sentence regarding the classification of exoplanets a. Mini-Neptunes: gas and ice planets larger than Earth but smaller than Neptune b. Hot Jupiter/Neptunes: gas and ice giants with orbital periods shorter than 10 days c. Super-Earths: planets slightly larger than Earth, rocky with a thin atmosphere d. Warm Jupiter/Neptunes: gas giants with temperature adequate to host liquid water Question 35 Mark the WRONG sentence regarding white dwarfs a. When they cool down, carbon assumes a crystalline configuration similar (but not exactly) to that of diamonds b. White dwarfs are very cold, so they are dim (low luminosity) despite their large size (several solar radii) c. Observed Hydrogen-Helium white dwarfs can only be the result of stellar evolution in binary systems d. White dwarfs have no energy source: they will gradually cool as they radiate their energy, becoming black dwarfs Question 36 What is a mean motion resonance? a. It is the synchronization of the rotational and orbital period for the same object b. The rotational periods of two objects are related by a ratio of small integers c. The orbital periods of two (or more) objects are related by a ratio of small integers d. It is the synchronization of the perihelion precession and of the ascending node Question 37 Mark the WRONG sentence regarding the Sun a.The Sun has a radiative core, extended up to 0.7 solar radii from the center, surrounded by a convective envelope b.In the Sun, only 19% of the energy is produced within 0.25 solar radii. Every second four tonnes of mass are converted into energy c.The observation of neutrinos from the core of the Sun has permitted their mass determination, awarded with several Nobel prizes d.composition has not changed since formation. In the core, 5% of the primordial Hydrogen has been converted to Helium Question 38 Mark the WRONG sentence regarding the magnetic activity of the Sun a.We have a prominence when the magnetic lines rise above the solar into a loop, and hot gas streams through the loop b.Sunspots are large regions (10000 km) in the photosphere that are around 1500K colder than the surroundings, appearing darker c.Differential rotation will cause the magnetic field to get wrapped and emerge from the surface, causing solar activity phenomena d.The lifetime of a single spot can be of several years. Spots appear and disappear randomly on the of the Sun Question 39 Mark the WRONG sentence regarding neutron stars and pulsars a.Neutron stars have a strong (compressed) magnetic field, because they preserved the magnetic field of the progenitors b.Only a small number of neutron stars emits a radio beam sweeping the sky regularly, and all of them take the name of pulsars c.Most neutron stars emit a radio beam, sweeping the sky regularly if the magnetic poles are not aligned with the rotation axis d.During the collapse the angular momentum of the core is preserved, so the emerging neutron star will spin extremely fast Question 40 Mark the WRONG sentence regarding the mass-temperature relationship in stars a. Stars become brighter, hotter (on surface) and less dense with increasing mass, but only for Main Sequence stars b. The CNO cycle is less sensitive to temperature, so in massive stars nuclear reactions occur at a much slower rate c.Massive stars need higher core temperatures to be stable, so that pressure can balance the higher gravitational compression d. Mass, luminosity and temperature are tightly correlated, with luminosity and temperature increasing with the mass Question 41 Ma rk the WRONG sentence regarding white dwarfs a.Electron degeneracy pressure can support a white dwarf of any mass, regardless of its origin b.The electron degeneracy pressure is independent of temperature, but it depends only on the density of matter c.White dwarfs are mainly composed of Carbon andOxygen, with a thin Hydrogen or Helium atmosphere d.Compression does not lead to heating and expansion as in regular stars: increasing the mass causes smaller radius Question 42 Mark the WRONG sentence regarding the lifetime of a star radiating as the Sun a.By radiating its gravitational potential energy, a star could only survive a few millions of years b.Chemical reactions or radioactivity are not efficient enough to justify the luminosity of the Sun c.Without any internal pressure to counterbalance gravity, a star would collapse in about half an hour d.Nuclear reactions keep a star in balance for billions of years only if all of its mass is converted to energy Question 43 Mark the WRONG sentence regarding hydrostatic equilibrium in stars a.Gravity of the underlying mass pulls the stellar material towards the center b.Gas pressure due to the thermal motions of the gas tends to expand the star outward c.In hydrostatic equilibrium, gravity and pressure counterbalance each other everywhere d.Hydrostatic equilibrium is naturally realized without requiring any source of energy Question 44 Mark the correct definition of the Vogt-Russell theorem а.Time it takes for the object to radiate away a significant amount of its gravitational potential energy b.The structure of a star, under given approximations, is uniquely determined by its mass and composition c.Luminosity and temperature of an ensemble of stars with the same age and chemical composition, over a wide range of mass d.A single star with a given mass and chemical composition is followed during its evolutionary stages Question 45 Mark the WRONG sentence regarding the horizontal branch phase in stellar evolution (intermediate-mass stars) a.During this phase, nuclear reactions are happening only in the core, and the rest of the star is unaffected b.The horizontal branch phase is characterized by Helium burning in the core of the star c.Triple-alpha reactions in the core require temperatures above 100 MK and produce Carbon and Oxygen d.The morphology of the Horizontal Branch in the colour-magnitude diagram depends on many parameters Question 46 Which is the main gaseous component of Titan atmosphere? a.Oxigen b.Hydrogen c.Nitrogen d.Carbon dioxide Question 47 Why are the outer planets bigger than the planets? а.In the outer region also He and H condensed, so there was more material then in the region b.Outer planets formed in a region in which more material condensed c. planets formed in a region with low content of material d.There was only rocky material in the region Question 48 The strong magnetic field of Jupiter has its origin from a. A wide layer of liquid molecular hydrogen in its interior b. A wide layer of liquid metallic hydrogen in its interior c. A wide layer of liquid Fe-Ni in its interior d. A wide layer of melted ices in its interior Question 49 Where do short period comets come from? a.The Kuiper Belt region b. The Main Belt regionca c.The Oort Cloud d.The Near Earth region Question 50 Where is the Main Belt a.Beyond the orbit of Neptune b.Beyond the Kuiper Belt c.Between the orbit of Mars and Jupiter d.Between the orbit of Jupiter and Saturn Question 51 Which is the most abundant ice in a comet? a.CO b.CO2 c.H20 d.CH4 Question 52 How does the cometary dust tail form? a.Interaction between cometary dust and solar radiation pressure b.Interaction between cometary dust and ions c.Interaction between cometary dust and cometary gas d.Interaction between cometary dust and solar wind Question 53 Which planet among the eight ones of the SS has the lowest density? a.Neptune b.Mars c.Saturns d.Mercury Question 54 Mark the WRONG sentence regarding the information stored by spectral lines a.Temperature and gravity can be iteratively determined when many lines of a given element are available b.In some conditions, it is possible to perform a direct comparison of the observed spectrum with theoretical models c.There is no relationship between the wavelength of the spectral lines and the relative velocity of the target d.Equivalent widths and shapes of spectral lines will depend on the abundance of the chemical elements in the photosphere Question 55 Mark the WRONG sentence regarding stellar spectral classification a.The Harvard classification introduced numbers to indicate intermediate type between spectral classes b.In the Revised Harvard classification, spectral types are now ordered by decreasing temperature c.The original classification by Secchi was based on distance, color, and luminosity of the stars d.The Draper Catalogue of Stellar Spectra rearranged the classes introduced by Secchi in letters. Question 56 Mark the WRONG sentence regarding the magnitude of a star а.The apparent magnitude alone can be used to derive the true brightness of the star b.The absorption caused by material between the star and the observer affects the magnitude c.The absolute magnitude is defined as the magnitude measured at a distance of 10 s from the star d.The difference between apparent and absolute magnitude is called distance modulus Question 57 Mark the correct sentence regarding the apparent and bolometric magnitude of a star a.The apparent magnitude can be obtained by knowing the flux density of a star, without the need of a second star b.The apparent magnitude is obtained by comparing the flux density of different stars at the same wavelength c.The bolometric magnitude can be easily measured with a single instrument from the ground. d.The apparent magnitude is obtained & by comparing the flux density of the same star at different wavelength Question 58 Mark the WRONG sentence regarding molecular spectra a.Vibrational transitions are less energetic than rotational ones b.Each electronic level is split in many additional levels of different origin c.Molecular bands are due to the blending of numerous spectral lines d.Energy levels can have rotational, vibrational or electronic origin Question 59 Mark the WRONG sentence regarding the different definitions of temperature of a gas or surface a.Brightness Temperature: temperature corresponding to a star with the same flux density of the Sun b.Kinetic Temperature: the temperature % of a gas defined by the average velocity of its particle Question 60 Mark the only sentence that correctly describes the effect of annual aberration for a star with ecliptic latitude equal to 45 degrees a.The amplitude of the aberration depends on the ecliptic longitude of the star b.The star will move along a line perpendicular to the Ecliptic c.The star describes an ellipsis with one axis perpendicular to the Ecliptic d.The star will move along a line parallel to the Ecliptic Question 61 Mark the only sentence that correctly describes the effect of annual aberration for a star with ecliptic latitude equal to zero degrees a.The star will move along a line perpendicular to the Ecliptic b.The amplitude of the aberration depends on the ecliptic longitude of the star c.The star describes an ellipsis with one axis perpendicular to the Ecliptic d.The star will move along a line parallel to the Ecliptic Question 62 Mark the dynamical effect with incorrect amplitude and period a.Planetary precession, amplitude 0.47 -arcseconds/year, secular b.Nutation, amplitude 9.2 arcseconds, period 18.6 years c.Polar motion, amplitude 0.3 arcseconds, 12 and 14 months d.Lunisolar precession, amplitude 23.5 arcminutes, period 2500 years Question 63 Mark the WRONG sentence regarding the Sidereal Time a.The Sidereal Time is equal to the sum & of Hour Angle and Right Ascension of a star b.The Sidereal Time is equal to the Hour Angle of the Vernal Point c.When the Vernal Point is crossing the Local Meridian, the Sidereal Time is equal to 0:00 d.When a star is crossing the Local Meridian, the Sidereal Time is equal to 0:00 Question 64 What are the Near Earth Objects? a. Objects (asteroids and/or comets) orbiting in a particular region of the Main Belt b. Objects (asteroids and/or comets) with high probability to impact the Earth c. Objects (asteroids and/or comets) with orbits close to the terrestrial one or that intersect it d. Objects (asteroids and/or comets) with orbits that intersect the terrestrial one Question 65 Mark the WRONG sentence, assuming that we are in the North hemisphere a.A star is always observable if its declination is smaller than the latitude of the observer b.A star is circumpolar if its declination is higher than the zenith angle of the North Pole c.A star reaches the maximum altitude when passing through the Local Meridian, in the South direction d.Only equatorial stars (declination=0) rise and set exactly at East and West, respectively Question 66 Mark the WRONG sentence, assuming that we are in the North hemisphere a. Every day Sun risse/sets in a different direction and at different time b. During the winter the Sun rise/sets closer to North than during the summer c. The Sun rise at East and sets at western exactly only during the equinoxes d. When the Sun crosses the Vernal Point, its declination chances significato from negative to’ positive Question 67 Mark the WRONG sentence regarding the classification of exoplanets a. Super-Earths: planets slightly larger than Earth, rocky with a thin atmosphere b. Hot Jupiter/Neptunes: gas and ice giants with orbital periods shorter than 10 days c. Mini-Neptunes: gas and ice planets larger than Earth but smaller than Neptune d. Warm Jupiter/Neptunes: gas giants with temperature adequate to host liquid water Question 68 Mark the WRONG sentence regarding the Habitable Zone.​ a. Greenhouse effect and irradiation from a gas giant (in case of moon) are not taken into account in its definition. b. A Planet in the Habitable zone can support liquid water on the surface, given sufficient atmospheric pressure c. The size of the Habitable Zone depends on the stellar type and effective temperature of the star d. A planet in the Habitable Zone most certainly will have liquid water and life on its surface Question 69 Mark the WRONG sentence regarding the magnetic activity of the Sun a. The lifetime of a single spot can be of several years. Spots appear and disappear randomly on the of the Sun b. Sunspots are large regions (10000 km) in the photosphere that are around 1500 K colder than the surroundings, appearing darker c. We have a prominence when the magnetic lines rise above the solar into a loop, and hot gas streams through the loop d. Differential rotation will cause the magnetic field to get wrapped and emerge from the surface, causing solar activity phenomena Question 70 Mark the WRONG sentence regarding the magnetic activity of the Sun a. Flares consist of a sudden increase & of energy stored in the magnetic field. They are among the most energetic events on the Sun b.Faculae are dark regions produced by an attenuation of the magnetic field. They are not associated to sunspots or distributed in a network c. Prominences and flares can accelerate particles in the corona. They can reach Earth within a few days and cause problems in communication systems d. Plages are the chromospheric counterparts of faculae associated to sunspots, and can be studied by observing the emission of specific spectral lines Question 71 Mark the WRONG sentence regarding neutron stars and pulsars a. Only a small number of neutron stars emits a radio beam sweeping the sky regularly, and all of them take the name of pulsars b. Neutron stars have a strong (compressed) magnetic field, because they preserved the magnetic field of the progenitors c. During the collapse the angular momentum of the core is preserved, so the emerging neutron star will spin extremely fast d. Most neutron stars emit a radio beam, sweeping the sky regularly if the magnetic poles are not aligned with the rotation axis Question 72 Mark the WRONG sentence regarding the Chandrasekar limit a. Passed the limit, electron degeneracy pressure is insufficient to balance the star's own gravitational compression b. Stellar remnants will become white dwarfs if below the limit, otherwise neutron stars or black holes if above the limit c. A star with mass around 8 solar masses will evolve to a stellar remnant with a mass close to the limit d. Photo-disintegration and neutronization provide pressure to the core and allow white dwarfs to be above this limit Question 73 Mark the WRONG sentence regarding the structure and lifetime of intermediate-mass stars a. In intermediate-mass stars, a radiative core is surrounded by a convective envelope b. A small transfer of material from the convective zone to the core allows an extended lifetime of the star c. Energy in the core is produced by proton-proton cycle and Carbon- Nitrogen-Oxygen cycle in equal parts d.These stars have lifetime of several billions of years. The Sun is 5 Gyrs old, and halfway its evolution Question 74 Mark the WRONG sentence regarding the transport of energy in a star a. Radiative transfer consists of energy transportation in the form of electromagnetic radiation b. Conduction is very inefficient because electrons (carrying energy) can travel only a short distance c. Convection starts when energy transport through radiative transfer (radiation) becomes inefficient d. In a star radiative and convective Zones can co-exist in the same region, acting simultaneously on the same material Question 76 Mark the WRONG sentence regarding the giant phase in stellar evolution a. Giant stars are colder on the surface, but hey are brighter because they have a larger than Main Sequence stars b. When Hydrogen is exhausted in the core, the star starts burning it in a shell surrounding an inert Helium core c. Stars in the giant phase have the same size and luminosity, regardless of their mass during the Main Sequence phase d. The Turn-Off is the point in the colour- magnitude diagram where the star leaves the Main Sequence to enter the Giant phase Question 77 Why are Venus and an exception in the Solar System? a. They do not have a magnetic field b. They have a thick atmosphere made of H c.They have a very slow rotation d.They have a retrograde rotation Question 78 How long is the orbital period of Jupiter? a. about 22 terrestrial years b. About 7 terrestrial years c. about 12 terrestrial years d. about 3 terrestrial years Question 79 What is the main component of Mars atmosphere? a. Nitrogen b. Carbon dioxide CO2 c. Carbon monoxide d. Methane Question 80 Why does Venus have no magnetic field? a. Because it is too close to the Sun b. Because its interior is completely solid c. Because of its slow rotation d. It has a magnetic field Question 81 The strong magnetic field of Jupiter has its origin from a.A wide layer of melted ices in its interior b.A wide layer of liquid Fe-Ni in its interior c.A wide layer of liquid molecular hydrogen in its interior d.A wide layer of liquid metallic hydrogen in its interior Question 82 The difference between primary and secondary planetary atmosphere is: a.The secondary atmosphere is made of methane and Hydrogen b.The primary atmosphere is made of Hydrogen c.The primary atmosphere is made of Hydrogen and Helium d.The secondary atmosphere is made of Oxygen and Hydrocarbons Question 83 Mark the WRONG sentence regarding the information stored by spectral lines a.There is no relationship between the wavelength of the spectral lines and the relative velocity of the target b.Equivalent widths and shapes of spectral lines will depend on the abundance of the chemical elements in the photosphere c.In some conditions, it is possible to perform a direct comparison of the observed spectrum with theoretical models d.Temperature and gravity can be iteratively determined when many lines of a given element are available Question 84 Mark the WRONG sentence regarding the measurement of radiation a.A radiation field is isotropic if the intensity is independent of direction b.The total intensity is obtained by integrating the specific density over a solid angle c.A source emitting radiation is isotropic fi its intensity is independent of the angle d.The specific intensity emitted from a depends on its frequency and direction Question 85 Mark the WRONG sentence regarding the measurement of radiation a.The flux density is the total amount of energy that crosses a unit area per unit time b.The luminosity is proportional to the inverse of the square of the distance of the source c.The total flux density is obtained by integrating the flux density over all frequencies d.The flux density of the Sun as measured on Earth is not constant during the year Question 86 Mark the WRONG sentence regarding the propagation of radiation in a medium (radiative transfer) a.The intensity at a given optical depth is independent of the emission by the medium b.If a cloud is optically thin, the source is attenuated but spectral properties are preserved c.If the cloud is optically thick, emission and absorption processes are in equilibrium d.There may be some conditions for which the radiation of a medium is equal to the blackbody radiation Question 87 Mark the WRONG sentence regarding blackbody radiation a.Both the intensity and the peak frequency of a blackbody increase with decreasing temperature b.Spectral distribution, total intensity, and flux of a blackbody only depend on its temperature c.A blackbody in thermal equilibrium emits electromagnetic radiation following the Planck's law d.A blackbody absorbs all incident electromagnetic radiation, and re-emits it completely Question 88 The calendar actually in use a.Is the Julian calendar b.Is the Proleptic calendar c.Is the Besselian calendar d.Is the Gregorian calendar Question 89 Mark the WRONG sentence a.UTC has the pace of TAI but origin always coincident, within 900 ms, with that of UT1 b.UT1, TAI and UTC are all continuous time standards, without discontinuities c.TAI is independent of astronomical effects and it flows at a constant rate d.UT1 is affected by the secular slowing down and by the non-uniformities of Earth rotation Question 90 Mark the element that is NOT required to define a celestial coordinate system a.The direction of one axis on the plane passing through the centre of the sphere b.The location of the centre of the reference system (e.g. or centre of Earth) c.The direction of the perpendicular of a plane passing through the centre of the sphere d.The radius of the sphere where the celestial objects are projected Question 91 Mark the WRONG sentence a. The difference between Apparent and Mean Sidereal Times is called Equation of Equinoxes​ b. The Apparent Sidereal Time can only be determined by mathematical approximations​ c. The Mean Equinox is the point where the vernal equinox would be if there was no nutation​ d. The Mean Sidereal Time is equal to the Hour Angle of the Mean Equinox Question 92 Mark the WRONG sentence regarding the core collapse of a massive star a. Right before the supernova explosion, the entirety of the mass of the star has been converted into Iron​ b. The star collapses on its core and then material bounces back in a very energetic supernova explosion​ c. Iron has the highest binding energy per nucleon, so its fusion cannot produce any energy​ d. Pre-supernova structure is formed by an Iron core surrounded by shells of progressively lighter elements Question 93 Mark the WRONG sentence regarding the structure and lifetime of high-mass stars a. On first approximation, massive stars live shorter because they need to burn more hydrogen to oppose gravity​ b. During its lifetime, a massive star is able to burn all the hydrogen in the core and outside the core​ c. Massive stars may become supernovae while other stars are still forming inside the same giant molecular gas​ d. In massive stars, a convective core is surrounded by a radiative envelope, with no exchange of material Question 94 Mark the correct definition of Right Ascension: a distance of the star from the Local Meridian along the Equator, measured anti-clockwise b. distance of the star from the Local Meridian along the Equator, measured clockwise c. distance of the star from the Vernal Point along the Equator, measured clockwise d. distance of the star from the Vernal Point along the Equator, measured anti-clockwise Question 95 Mark the only sentence that can be referred to alt-azimuthal mounts a. You necessarily need two engines to follow the stars during the night b. No restrictions in pointing, except for the North pole c. The dome may be much larger than the telescope structure d. No field rotation during long exposures Question 96 Mark the WRONG sentence a. The average temperature of the whole Earth at aphelion is higher than at perihelion b. The perihelion happens during the Northern summer, precisely the 3rd of July c. Warm seasons in the Northern hemisphere last 7 days longer than the Southern one d. At aphelion Earth receives approximately 7% less energy than at perihelion Question 97 Mark the WRONG sentence regarding the definition of magnitude +a. The magnitude of a star increases logarithmically with the decrease in its flux density b. Hipparchus introduced the concept of magnitudes by dividing the naked-eye stars into six groups c. Pogson determined that stars of 6th magnitude are 10000 times brighter than those of 1st magnitude d. Magnitudes are based on the relationship between the perceived change and the actual stimulus Question 98 Mark the WRONG sentence regarding the different spectroscopic techniques a. Gratings rely on the constructive and destructive interferences of light beams b. A grism allows low-resolution spectroscopy of a large number of objects at the same time c. Prism can produce spectra thanks to the dependency of the refractive index with wavelength d. In gratings, both the spectral resolution and the intensity decrease with increasing order Question 99 Mark the WRONG sentence regarding stellar spectral classification A. O-B-A classes include blue-white stars with temperatures between 50.000 and 7.500 K b. M-L-T classes include red and brown stars with temperatures above 50.000 K c Classes are grouped into early-solar- and late type according to their temperature X d. F-G-K classes include yellow-orange stars with temperatures between 7.500 and 3.500 K Question 100 Mark the WRONG sentence regarding stellar spectral classification a. C-S stars show peculiar absorption lines in their spectra​ ​ b. M-L-T stars do not show any feature in their spectra c. O-B-A stars are characterized by strong and/or He lines due to their high temperatures d. F-G-K stars have spectra very similar to the to the one of the Sun Question 101 What is the most unusual property of : a. the inclination of its axis b. Its ice composition c. the presence of methane in its atmosphere d. Its prograde orbital motion Question 102 Mark the WRONG sentence regarding the asymptotic giant phase in stellar evolution (intermediate-mass stars) a. The star becomes unstable due to the presence of two shells with fusion reactions, Hydrogen and Helium respectively b. The star will lose the outer envelope into space, the expelled material take the name of planetary Nebula c. The outcome of this phase will be a White Dwarf either made of Carbon and Oxygen, or just exclusively Helium d. When the Helium in the core is exhausted, Helium keeps burning in a shell leaving behind a Carbon and Oxygen core Question 103 Mark the WRONG sentence regarding neutron stars a. A newly formed neutron star has a temperature of one billion degrees, a strong magnetic field and it spins extremely fast b. A neutron star with mass 1.44 solar masses has a radius of just 10 km and a density similar to those of atomic nuclei c. During the final collapse of a star, the totality of its mass is converted to neutrons, with no ejection of matter d. Further collapse of neutron stars is avoided by the neutron degeneracy pressure, if the mass is below the TOV limit Question 104 Mark the WRONG sentence regarding black holes a. If a mass is contained within its Schwarzschild radius, its gravitational field is so strong that light cannot escape, regardless of its density b. The event horizon is a boundary at the Schwarzschild radius beyond which events cannot affect an observer outside c. If a neutron star is more massive than the Tolman-Oppenheimer-Volkoff limit, the neutron degeneracy pressure is insufficient to stop the collapse d. A supernova remnant will always become a black hole, regardless of the ejected mass during the supernova explosion Question 105 Mark the WRONG sentence regarding stellar clusters and association a. Open clusters and associations are randomly distributed in the galactic disk, so they do not provide any information on the shape of the Milky Way b. The distances of stars in a cluster are much easier to measure than for single stars, allowing the computation of their absolute luminosity c. Globular clusters are spherically distributed around Galactic centre, so their distance can be obtained by studying their apparent distribution around Earth d. Stars belonging to a cluster have the same age but different masses, so they will naturally draw an isochrone in the Hertzsprung-Russel diagram Question 106 Mark the WRONG sentence regarding photometric systems a. The magnitude of a photometric system depends strongly on the wavelength intervals where the flux density is measured b. In the post a photometric system was defined by a strict combination of optics, instruments and photometric filters c. A modern photometric system is completely defined by the description of the filter response as a function of wavelength d. The first photometric systems were defined according to the response of the naked eye and/or photographic plates Question 107 Mark the WRONG sentence regarding modern photometric systems a. The Johnson-Cousins-Glass system includes bands in the infrared due to the higher sensitivity of CCDs b. Some photometric systems are characterized by vera narrow bands,… c. The original Johnson-Morgan system only included three bands: ultraviolet U, blue B, visual V d. Photometric measurements from different observatories can be mixed, even if filters are slightly different Question 108 What is the main component of Venus atmosphere? a. Nitrogen b. Carbon dioxide c. Carbon monoxide d. Methane Question 109 Mark the WRONG sentence regarding the detection techniques of exoplanets a. The Transit technique is the least successful method for planet detection b. The true mass of the planet can be optai ed only if its orbital inclination is known c. The Radial Velocity technique allows the ssmeasurement of the minimum mass of a planet d. It is possible to observe a planet with both the transit and the radial velocity Question 110 Mark the WRONG sentence regarding the meridian telescope a. The right ascension and declination of a star can be precisely measured b. The concept of meridian telescope can be extended to radio observation as well c. A meridian telescope is fixed in right ascension and can be moved only in declination d. A star with known right ascension can be used to directly measure the Universal time Question 111 Mark the only cause of perturbation of coordinate that is not related to the movements of Earth a. Refraction b. Parallax c. Aberration d. Precession Question 112 Mark the correct sentence regarding the transition between energy levels a. Emission is a bonus-free transition b. Recombination is a free-bound transition c. Ionization is a free-bound transition d. Absorption is a bound-bound transition Question 113 Venus has a. Two rings b. A thick atmosphere that … c. two small satellites d. A mass similar to that of the Earth Question 114 Which mission is not dedicated to the detection or characterization of exoplanets? a. EUCLID - EUropean Constellation for exoLife Detection, NASA b. TESS - Transiting Exoplanet Survey Satellite, NASA c. PLATO - PLAnetary Transits and Oscillations of stars, ESA d. CHEOPS - CHaracterising ExOPlanet Satellite, ESA Question 115 Mark the system that is exclusively topocentric a. Equatorial system b. Ecliptic system c. Horizontal system d. Galactic system Question 116 Mark the wrong sentence regarding the Bohr model of an atom a. The energy level of electrons can not assume arbitrary values b. If an electron is not in the ground state, the atom is in an excited state c. Electrons orbit around a nucleus composed of protons and neutrons d. Electrons jumps from the ground state are the less energetic ones Question 117 Mark the wrong sentence regarding flux and luminosity a. The flux is the power going through some and it is measured in Watt b. The flux passing through a closed encompassing the source is called luminosity c. The flux density and the Solar constant do not depend on the distance of the source d. In the absence of absorption, the luminosity is constant regardless of the distance of the source Question 118 Mark the WRONG sentence regarding the structural properties of galaxies a. Dust is concentrated in the thin disk, this is why the Milky Way’s bulge appears split in two b. The Halo is mostly composed of neutral gas, visible only in the radio range, and old stars c. Bars are thought to be streams of gas from the spirals to the centre of the galaxy d. Spirals are fixed structures that revolve rigidly around the bugle of a galaxy Question 119 Mark the WRONG sentence regarding the giant phase in stellar evolution a. Giant stars are colder on the surface, but hey are brighter because they have a larger than Main Sequence stars b. The Turn-Off is the point in the colour-magnitude diagram where the star leaves the Main Sequence to enter the Giant phase c. When Hydrogen is exhausted in the core, the star starts burning it in a shell surrounding an inert Helium core d. Stars in the giant phase have the same size and luminosity,regardless of their mass during the Main Sequence phase Question 120 Mark the WRONG sentence regarding neutron stars a. During the final collapse of a star, the totality of its mass is converted to neutrons, with no ejection of matter b. A newly formed neutron star has a temperature of one billion degrees, a strong magnetic field and it spins extremely fast c. A neutron star with mass 1.44 solar masses has a radius of just 10 km and a density similar to those of atomic nuclei d. Further collapse of neutron stars is avoided by the neutron degeneracy pressure, if the mass is below the TOV limit Question 121 Mark the WRONG sentence regarding the asymptotic giant phase in stellar evolution (intermediate-mass stars) a. When the Helium in the core is exhausted, Helium keeps burning in a shell leaving behind a Carbon and Oxygen core b. The outcome of this phase will be a White Dwarf either made of Carbon and Oxygen, or just exclusively Helium c. The star becomes unstable due to the presence of two shells with fusion reactions, Hydrogen and Helium respectively d. The star will lose the outer envelope into space, the expelled material take the name of Planetary Nebula Question 122 What is the frost line? a. The boundary between Neptune and the Kuiper Belt b. The boundary between and outer planets c. The boundary between the Kuiper Belt and the Oort Cloud d. The boundary between the Sun and the present orbit of Mercury where no material could condense Question 123 Mark the element that is not required for the operational definition of an apparent magnitude a. Spectral energy distribution of the star (flux density as a function of wavelength) b. Properties of calibration stars (position, proper motion and parallax of each star) c. Detector and instrumental characteristics (reflectivity of the optics and CCD efficiency) d. Filter to select a specific wavelength range (transmission curve) Question 124 Mark the WRONG sentence a. The Apparent Sidereal Time can only be determined by mathematical approximations b. The difference between Apparent and Mean Sidereal Times is called Equation of Equinoxes c. The Mean Equinox is the point where the vernal equinox would be if there was no nutation d. The Mean Sidereal Time is equal to the Hour Angle of the Mean Equinox Question 125 Mark the correct definition of Hour Angle a. distance of the star from the Vernal point along the Equator,measured anti-clockwise b. distance of the star from the vernal point,along the Equator measured clockwise c. distance of the star from the Local Meridian along the Equator, measured clockwise d. distance of the star from the Local Meridian along the Equator, measured anti-clockwise Question 127 Mark the WRONG sentence regarding instrumentations to characterize exoplanets a.Synergy (collaboration) between ground and space-based observatories is nearly impossible to obtain b. Most of the small transiting planets have been discovered by space observatories c. Radial velocity technique requires extremely well-calibrated instruments, usually from the ground d. Atmosphere characterization can be performed either from ground (spectroscopy) or space (photometry) Question 128 Mark the WRONG sentence a. The orbital eccentricity of Earth greatly influences the Equation of Time b. The equation of Time is the difference between the Mean Equinox and the Mean Solar Time c. The analemma can be thought as a visual representation of The Equation of Time d. There is a strong dependency of The Equation of Time on the obliquity of the Ecliptic Question 129 Mark the WRONG sentence regarding the structure and lifetime of low-mass stars a. At the end of their life, low-mass stars will evolve into Carbon-Oxygen white dwarfs and slowly cool down b. The lifetime of low-mass stars can be extended up to trillion of years, i.e., longer than the age of the universe c. These stars are fully convective, so the entirety of its mass can be used as fuel for fusion reactions d. At some point the universe will consist only of low-mass, cold stars, since they are also favoured in stellar formation Question 130 Mark the WRONG sentence regarding the properties of light a.Electromagnetic radiation propagates as both electrical and magnetic waves b.Photons are packets, or quanta, of continuos and variable amounts of energy c.Light can be described simultaneously as a wave and as a particle d.A photon has energy and momentum, but no mass and electric charge Question 131 Mark the correct definition of an isochrone a.Time it takes for the object to radiate away a significant amount of its gravitational potential energy b.A single star with a given mass and chemical composition is followed during its evolutionary stages c.The structure of a star, under given approximations, is uniquely determined by its mass and composition d.Luminosity and temperature of an ensemble of stars with same age and chemical composition, over a wide range of mass Question 132 Mark the WRONG sentence regarding the formation of protostars​ a. In the first phase of protostar formation, the gas is optically thin and the gas collapses in a free fall regime​ b. The actual protostar phase begins when the hydrostatic equilibrium settles in​ c. Perturbations in molecular clouds will form overdensities (Bok Globules or Dark Nebulae) that will become protostars​ d. During the protostar phase, the central temperature in the core is high enough for Hydrogen fusion