Homeworks 12: Difference between revisions
| Line 16: | Line 16: | ||
===Lecture 6=== | ===Lecture 6=== | ||
# Yearly parallax of a star is 0.1 arcsec. What is its distance? | # Yearly parallax of a star is 0.1 arcsec. What is its distance? | ||
# | #* 10 | ||
# | # The electric and gravitational --- (in Newton's limit) are both scalar | ||
# | # Absolute magnitude is | ||
#* the measure of luminosity of an object | |||
# Light is both particle and wave because otherwise | |||
#* atoms would not be stable | |||
==Lecture 8== | |||
# Besides the radio, ground-based observatories allow to observe in the wavelength range of | |||
#* optical to infrared | |||
# By photometry of astronomical object, we measure | |||
#* the apparent brightness | |||
# Which of the following effects limit the imaging in reflector telescopes in prime focus? | |||
#* spherical aberration | |||
#* '''chroma''' | |||
#* chromatic aberration | |||
==Lecture 12== | |||
===Lecture 8=== | ===Lecture 8=== | ||
Revision as of 21:52, 10 December 2009
Review for the Final on 12/11/2009
Mini-Quizzes
Lecture ?
- How long does sunlight take to get to the next star?
- 8 minutes
- How long is a typical galaxy
- 10,000 Lys
- In azimutal coordinates, the positions of star change due to
- the rotation of the Earth
- Peticular velocity is the projected velocity of
- a star relative to other stars
Lecture 6
- Yearly parallax of a star is 0.1 arcsec. What is its distance?
- 10
- The electric and gravitational --- (in Newton's limit) are both scalar
- Absolute magnitude is
- the measure of luminosity of an object
- Light is both particle and wave because otherwise
- atoms would not be stable
Lecture 8
- Besides the radio, ground-based observatories allow to observe in the wavelength range of
- optical to infrared
- By photometry of astronomical object, we measure
- the apparent brightness
- Which of the following effects limit the imaging in reflector telescopes in prime focus?
- spherical aberration
- chroma
- chromatic aberration
Lecture 12
Lecture 8
Midterm 1
The test consists of a combination of multiple choice questions and other questions which count for 1/3 and 2/3 of the scores, respectively. For partial credit, feel free to add a sentence for the multiple choice questions, and write down the individual steps.
Problem 1A
The proper motion of a star is caused by
- (a) The earth orbiting the sun
- (b) The velocity of the star relative to us
- (c) The orbit of a star within a binary system
- (d) The transverse velocity of the star relative to us
Problem 1B
How are continuum, absorption, and emission line spectra produced? Name the basic types of transitions in an atom. Name one physical process for each of them. Name 2 classes of astronomical objects for each of them.
Problem 2A
Other than the equations for microscopic physics (EOS, nuclear reactions, atomic physics), the basic equations of stellar structure are (mark all which apply):
- (a) Newton's laws
- (b) Pressure equilibrium
- (c) Conservation of mass
- (d) Wave equation
- (e) Momentum transport
- (f) Energy generation
- (g) Energy transport
Problem 2B
Problem 3A
Suppose two stars 1 and 2 are identical in every respect but star 2 is 100 times further away. If the apparent magnitude of star 1 is 10 mag, the apparent magnitude of star 2 is:
- (a) 0
- (b) 5
- (c) 10
- (d) 15
- (e) 20
The answer is NOT (b).
Problem 3B
Problem 4A
A white dwarf star is smaller than a main sequence star of the same effective temperature by a factor of:
- (a) 1
- (b) 10-2
- (c) 101
- (d) 10-4
- (e) 10-3
Problem 4B
Problem 5A
Two stars A and B have the same temperature, but their absolute brightnesses are 0 and +5 mag, respectively. Star A is brighter than Star B by a factor of:
- (a) 0.01
- (b) 0.1
- (c) 1
- (d) 10
- (e) 100
The answer is NOT (a) or (b)