Modern Astronomy 29:050

Exam 2

Mar 3, 2004.

This is a closed book (and notes) exam. Calculators are allowed.

All exams will be collected at 1:20pm.

a.        Reflection nebulae

b.        Emission nebulae

c.        Dark nebulae

d.        Reflection and dark nebulae

e.        Emission and dark nebulae

Note: This question had NO correct answer! There’s a typo: response (b) had hydrogen

and helium reversed. I am scoring this as correct on all exams for all answers.

a.        The Sun is a post-main sequence star

b.        The Sun is converting helium to hydrogen in the core

c.        The Sun’s interior transports energy only by convection

d.        The Sun’s photosphere is hotter than the interior

e.        The Sun’s core is not a source of neutrinos

a.        Hydrogen

b.        Helium

c.        Lithium

d.        Argon

e.        All of these

a.        Magnetic storms

b.        Neutrino flux from core

c.        Hydrogen fusion

d.        Radiative heat transport

e.        Sunquakes

a.        High magnetic fields in sunspots

b.        Very high temperature in the solar corona

c.        Rapid rotation near the solar equator

d.        Polarization caused by reflections in the photosphere

e.        Unusually large solar vibrations with 5 min period

a.        Solar neutrinos have been detected on Earth in deep mines

b.        Most solar neutrinos pass through the Sun’s interior without interacting

c.        Solar neutrinos are created by thermonuclear processes in the core

d.        Solar neutrinos have different ‘flavors’

e.        Most solar neutrinos are absorbed by the Earth’s dense core

a.        The Sun rotates like a solid body, with a period of 26 days at all latitudes

b.        The Sun rotates differentially, fastest at the poles

c.        The Sun rotates differentially, fastest at the equator

d.        The Sun’s rotation varies from 20 days at the S pole to 40 days at the N pole

e.        The Sun’s rotation varies from 25 to 35 days depending on solar cycle

a.        Heliomagneticism

b.        Helioseismology

c.        Heliogravitation

d.        Helioradiation

e.        Angular momentum studies

a.        2 parsec

b.        5 parsec

c.        20 parsec

d.        50 parsec

e.        200 parsec

a.        Star A is half as luminous as Star B

b.        Star A is twice as luminous as Star B

c.        Star A is four times as luminous as Star B

d.        Star B is four times as luminous as Star A

e.        Star A is the same luminosity as Star B

a.        1/16 the luminosity of the Sun

b.        1/4 the luminosity of the Sun

c.        Half the luminosity of the Sun

d.        Twice as luminous as the Sun

e.        Four times the luminosity of the Sun

a.        Star A is brighter than star B; both could be seen with an unaided eye.

b.        Star A is brighter than star B, but only star A could be seen with an unaided eye.

c.        Star A is dimmer than star B; both could be seen with unaided eye.

d.        Star A is dimmer than star B; only star B could be seen with unaided eye

e.        Star A is dimmer than star B; both are too dim to be see with an unaided eye

a.        Both stars are evolved (post main-sequence)

b.        Both stars have approximately the same luminosity

c.        Both stars have approximately the same surface temperature

d.        Sirius has a larger radius than Deneb

e.        Both stars are supergiants

a.        M1V

b.        K5IV

c.        O9V

d.        A5IV

e.        G2V

 

 

 

a.        The ‘star’ Algol actually consists of two stars

b.        The two stars have very unequal luminosities

c.        The orbital period is approximately 68 hrs

d.        The observer’s line of sight is nearly in the orbital plane

e.        The dimmer star is much smaller than the brighter star

a.        Both have nearly the same surface temperature

b.        Both have similar luminosities

c.        Both have similar spectral lines, but star B’s lines are narrower

d.        Both are cooler than the Sun

e.        Star B is much more luminous than the Sun.

a.        Ultraviolet radiation from O and B stars

b.        Shocks from supernovae

c.        Heating from superheated dust

d.        Magnetic compression of plasma

e.        Dust scattering light from nearby stars

a.        Localized gravitational evacuation of stars

b.        Nearby (solar system) clouds orbiting the Sun

c.        Cold dust

d.        Regions of extremely underluminous stars

e.        Supernovae blasts evacuating the region

a.        Star A is more luminous than star B

b.        Star B is more luminous than star A

c.        Star A is farther away than star B

d.        Star B is farther away than star A

e.        Someone made a mistake! Same spectral type always means same color

 

 

 

 

 

a.        Low-mass stars (<1 solar mass) are on main-sequence

b.        The age of this cluster is less than 100 million yrs

c.        The age of this cluster is between 5 and 10 billion yrs

d.        Massive stars (>1 solar mass) have evolved into giants and supergiants

e.        There are cool stars (~3,000K) with luminosities much less and much larger than the Sun

a.        In cold, dense clouds

b.        In hot, tenuous clouds

c.        In cold, tenuous clouds

d.        In highly evolved supergiant stars

e.        In protostars

a.        chemical composition

b.        location in the star formation region

c.        the amount of dust in its outer envelope

d.        mass

e.        rotational period

a.        Main-sequence  :  less  mass :  pre-main sequence

b.        K5V   :  more  mass :  B5V

c.        M1Ia   :  more mass  :  M1V

d.        More massive  :  shorter lifetimes  : less massive

e.        More luminous : larger radii  : less luminous

a.        They are all fusing hydrogen into helium in the core

b.        They all have dense carbon inner cores

c.        They all move up the main-sequence to the OB stage

d.        They all have the same lifetime on the main-sequence

e.        They all  have helium absorption lines in their spectra

a.        radiative and convective shells

b.        only a radiative shell

c.        only a convective shell

d.        only a conductive shell

e.        only a core