Download quiz 1 Spring 1995

Key
Phys 102 Astronomy
Name _____________________
EXAM 2: LIGHT AND STARS: BRAIN AND PENCIL
This part of the exam is to be completed by yourself with no references. When
you finish, hand it in, pick up the Group part of the exam.
1)12 Complete the following table:
CELESTIAL
EVENT
DEFINITION
VERNAL
SUN ON CELEST. EQ.
EQUINOX
MOVING NORTH
SUMMER
SUN AT NORTHERNMOST
SOLSTICE
POINT
AUTUMNAL
SUN ON CELEST. EQ.
EQUINOX
MOVING SOUTH
WINTER
SUN AT SOUTHERNMOST
SOLSTICE
POINT
α
δ
HOURS
DEGREES
CONSTELLATION
(NAME)
SUBSOLAR
LATITUDE
APPROX.
DATE
0h
0°
Pisces
Equator
3/21
6h
+23.5°
Taurus
Tropic of
Cancer
6/21
12h
0°
Virgo
Equator
9/21
18h
-23.5°
Sagittarius
Tropic of
Capricorn
12/21
Multiple Choice: circle the best answer (or split the points by circling two)
2)2 The color of a star is a direct measure of its
a) mass.
b) temperature.
c) velocity.
3)2 The moon’s current phase is
a) waxing crescent.
b) waxing gibbous.
c) waning gibbous.
d) waning crescent.
4)2 Today the sun will set
a) south of due east.
b) south of due west,
c) north of due east,
d) north of due west,
5)2 The celestial equator is
a) the path of the sun across the stars.
b) a cosmic referee who is responsible for making things "fair."
c) the projection of the earth's equator onto the celestial sphere.
d) the line from due north to due south that passes through the zenith for an observer.
6)2 One element differs from another in
a) the number of neutrons.
b) the number of electrons.
c) the number of protons.
Stars
E
n
e
r
AOD 4/3/2006
A
B
Wavelength
7)2 Of the two stars whose continuum spectra are shown
a) A is cooler.
b) A is more distant.
c) B is cooler.
d) B is more distant.
8)2 An atom is said to be in an excited state when
a) it visits California.
b) electrons are removed.
c) electrons are in higher energy levels than normal.
9)4 Tonight, (Mar. 29) ρ Leo, a B0I supergiant, will transit at 10:04 PM. On what night will it, or
did it transit at 10:00 PM? (Sketch it to help yourself figure it out ... tonight’s situation is shown)
a) March 25th.
Observer’s
b) March 28th.
Meridian
c) March 30th.
d) April 2nd (March 33rd).
10)2 Total Eclipses of the sun can only occur when
a) the moon is new.
b) the moon is full.
c) the line of nodes is perpendicular to the Earth-Sun line.
Sol @
10:04 pm
11)2 If you see the moon rising at 3 pm, the phase must be
a) waxing crescent.
b) waxing gibbous.
c) waning crescent.
The birth of dawn from sun and darkness is a d) waning gibbous.
mystery very sacred though it happens every day.
‐‐ Pawnee song
12)2 The declination of a star is
a) the angle between it and the celestial equator.
b) the angle between it and the horizon.
c) the angle between it and the point of Aries.
13)2 The altitude of a star is
a) its height above the ground.
b) its angle from the celestial equator.
c) its angle above the observer's horizon.
14)2 The Sun is an average star of spectral type
a) G5 II.
b) G2 V.
c) F3 IV.
Page 2
Stars
AOD 4/3/2006
15)10 Identify the phase of the moon in the following images:
Phase:
3rd Quarter
Phase:
Phase:
Waxing
Gibbous
Phase:
New
Full
Phase:
1st Quarter
16)9 label the diagrams below with the sun and the moon (in the appropriate phase) for observations of the
moon with the given elongations and times. The observer is looking south, into the page.
E
W
a) 90° W @ 3
PHASE:
st
AM
1 Quarter
______________
E
W
b) 135° E @ 3 PM
PHASE:
Wax. Gibbous
______________
17)8 For the images to the right, explain what they tell us about star
formation and evolution. What stage does each represent? Has or will
our sun go through a similar stage? Name at least one nebula (and its
constellation) where stars are at the same stage in life.
The top image is of a planetary nebula (with a central
white dwarf). It shows the death stage of a small (sunsized) star and Sol will go through this stage in about 5
billion years. Another such nebula is the Ring Nebula in
Lyra.
The lower image is of a star formation in the Eagle
Nebula in Serpens. In this image, the stellar wind from
a bright star to the upper right is evaporating the gas
and dust, leaving dense evaporating gaseous globules
(EGGs) where stars are forming. The sun may have
gone through this 5 billion years ago when it formed.
Page 3
E
W
c) 45° E @ 6 PM
PHASE:
Wax. Crescent
______________