Modern Astronomy

Final Exam Key14 May  2004

 

This is a closed book exam. A list of relevant equations is attached to the back. Please mark the correct response to each question in the answer key provided.

 

1)      What observational evidence supports the model that quasars have sizes less than one parsec?

a)      large luminosity

b)     rapid  [hourly- weekly] time variations

c)      central location in a galaxy

d)      large distances

e)      energetic jets

 

2)      On the celestial sphere, the circle which is located  90° from the north celestial pole is the

a)      ecliptic plane

b)      prime meridian

c)      celestial horizon

d)     celestial equator

e)      Line of nodes

 

3)      At approximately what time does the waxing quarter moon rise?

a)      sunset

b)      sunrise

c)      noon

d)      midnight

e)      3 pm

 

4)      On which date(s) is the Sun in the ecliptic plane?

a)      December 21

b)      March 21 and September 21

c)      June 21

d)     All days

e)      Never

 

5)      Which statement best describes the likely evolutionary history of an M-type star?

a)      Main-sequence, supergiant, supernova, total lifetime less than 10 million yrs

b)      Main-sequence, giant, planetary nebula, white dwarf, total lifetime 1 billion years

c)      Main-sequence, bright giant, AGB branch, lifetime 10 billion years

d)      Main-sequence, white dwarf, lifetime at least 15 billion yrs

e)      Main sequence, giant, white dwarf, lifetime >30 billion yrs

 

6)      A Type I supernova results from

a)      A massive post-main sequence massive star which has depleted its fusion ‘fuel’

b)      A post main-sequence star after the ‘helium flash’

c)      A neutron star which has suffered magnetic ‘starquake’

d)     A white dwarf in a binary star in which the companion transfers excessive mass

e)      A black hole which ‘swallows’ a solar-mass star

 

7)      A common characteristic of all stars on the main-sequence is

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

 

8)      An object with an angular size of 1 arcminute moves three times farther away. What is its new angular size?

a)      3 degrees

b)      20 arcminutes

c)      3 arcminutes

d)     20 arcseconds

e)      3 arcseconds

 

9)      Which key experimental test was performed after Einstein’s groundbreaking paper describing General Relativity of 1916?

a)      Gravitational redshift of Sirius-B

b)      Precession of Mercury’s orbit

c)      Time dilation of fast-moving observers

d)      Tidal distortion of an object near a massive object

e)      Deflection of starlight near the Sun

 

10)   Which of the following stars of specified spectral type is the least massive?

a)      M1V

b)      K5IV

c)      O9V

d)      A5IV

e)      G2V

 

11)  A parsec is:

a)      the distance between the Sun and Earth

b)      the distance between the Earth and Moon

c)      The approximate distance to nearest galaxy

d)      the angle between the sun and  nearest star

e)