Transcript The hierarchical structure of the Universe (go from little to large)

Prepare your scantron:
Use
• Fill in your name and fill the bubbles under a pencil,
your name.
not a pen!
• LAST NAME FIRST, First name second
• Put your 4-digit code instead of
“IDENTIFICATION NUMBER”.
--- (The last 4 digits of your OleMiss ID.)
Recall reading assignment
Chapter 1, pp. 1 – 26
Question # 1: answer A
Setup: Question # 2: answer A
Question # 3: answer A
Review questions on Monday – Be sure to prepare.
Please take a moment to mute your cell phone!
Constellations and designations of stars
Constellation = random collection
of stars (figure)


Stars’ names:
Greek letter + constellation name
 Orionis (= Betelgeuse)
 Orionis ( No special name)
 Canis Majoris (= Sirius)



More star names
Find:
 Leporis
 Geminorum
 Tauri
A few distances:
 Canis Maioris - 9 ly
 Canis Maioris - 500 ly
 Canis Maioris - 1,800 ly
 Canis Maioris - 430 ly
95% of the 6,000 naked-eye
stars are at 50 to 500 ly:
in the solar neighborhood.
Inside Taurus!
Questions coming …
Question 4
Which constellation is closer to us,
and how do we know?
A
The Big Dipper is closer than Orion because
the Big Dipper looks larger in the sky.
B
Orion is closer than the Big Dipper because
Orion’s stars look brighter in the sky.
C
D
All constellations are at the same distance.
E
45
25
30
35
40
12
13
14
15
16
17
18
19
10
11
20
4321087659
sec
This question is nonsense because constellations
are not real objects.
This question is nonsense because the distance to constellations
changes as Earth revolves around the Sun.
Next question coming …
Question 5
What is  Canis Maioris?
A The name of a bright star.
B The name of a planet.
C The name of a constellation.
D A galaxy.
E The name of a moon revolving
30
29
12
13
14
15
16
17
18
20
21
22
23
24
25
26
27
28
10
11
8765432109
19
sec
around the planet  Canis Maioris.
Next question coming …
Question 6
30
29
12
13
14
15
16
17
18
20
21
22
23
24
25
26
27
28
10
11
8765432109
19
The Pleiades (the “Seven Sisters”) is …
A A constellation.
B A star.
C Not a constellation, but it is a star cluster inside
sec
the constellation of Taurus.
D A constellation, which is the same thing as a star cluster.
E A collection of seven random stars, unrelated to each other.
Next question coming …
Question 7
Most of the stars visible in the sky by the naked eye are …
45
25
30
35
40
12
13
14
15
16
17
18
19
10
11
20
4321087659
A outside the Galaxy.
B inside the Galaxy, but not necessarily in the vicinity
of the Sun.
C inside the Galaxy, and mostly in the vicinity
of the Sun.
D 50% inside the Galaxy, 50% outside.
E nowhere close to the Galaxy, which is much farther away
from us than the individual stars in the sky are.
sec
An observational perspective on real astronomy.
Stars are always dots in the telescope:
Star with naked eye:
Star in a telescope:
Must analyze spectrum (color) of stars to learn about them - a hard job!
All else in the sky if faint: “deep sky” objects
Must collect light for a long time with large telescopes - a hard job!
With the
naked eye
The
Milky
Way
Photography
(30 minutes)
Look in a telescope
Questions coming …
Question 8
30
29
12
13
14
15
16
17
18
20
21
22
23
24
25
26
27
28
10
11
8765432109
19
How does a star look in a good telescope?
A A large disk with swirls of hot gas visible on it.
B A large disk with mountains and rivers visible on it.
C A large disk with clouds visible on it.
D A small disk with a few starspots.
E A bright dot.
sec
Next question coming …
Question 9
30
29
12
13
14
15
16
17
18
20
21
22
23
24
25
26
27
28
10
11
8765432109
19
Is the Milky Way visible to the naked eye
in a dark location?
A No. We need large telescopes to see the
Milky Way at all.
sec
B No, but a pair of binoculars is sufficient to see it.
C Barely.
D As a faint and tiny patch of glow.
E As a band of light all the way around the sky.
Next question coming …
Question 10
What is the light of the Milky Way in actual fact?
30
29
12
13
14
15
16
17
18
20
21
22
23
24
25
26
27
28
10
11
8765432109
19
A The light of a few billion stars washed together.
B A reflection of sunlight in Earth’s atmosphere.
C A reflection of sunlight on dust particles in the
sec
Solar System.
D The glow of the upper atmosphere due to cosmic radiation.
E The glow of gas left behind when the Universe was born.
What is in the sky?
All outside the Solar System,
remember?
- Stars (in constellations)
- Everything you see is part of the Galaxy
• The glow of the Milky Way
• Stars
• Star clusters (open clusters and globular clusters)
• Planetary nebulae (dying stars)
• Supernova remnants (stars that blew up)
• Diffuse nebulae (glowing interstellar gas)
The
Messier
Catalog
M1 through M104
- Except: other galaxies.
Only 3 other galaxies to the naked eye:
• The Andromeda Galaxy
• The Small Magellanic Cloud (southern)
• The Large Magellanic Cloud (southern)
Explain what
is each one,
do pictures
again.
Take notes of
what is said!
… and there is the Solar System of course.
This is what you would see in a very good telescope.
Solar System
Sun
Moon
Mercury Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
M 57
With the naked eye
A planetary nebula a dying star
The Ring Nebula
Photography
(90 minutes)
Look in a telescope
(Picture taken in
Kennon
by two students)