ASTRO 7N - UNIT 4 PART 1 (convo)
Eagle Nebula: How are stars being formed here?
Shock waves from heated gas are crashing into colder gas and compressing it, allowing stars to form.
Orion nebula: What causes those arcs and bubble shapes in the dust and gas distribution of Orion?
Stellar wind from local stars
The brightest stars in the Pleiades are B and A Main Sequence stars. How old do you suppose that cluster is then?
Tens to a hundred million years old
What is one way the concentric rings in the Cat's Eye nebula might have formed?
The gas might have been ejected in pulses.
The ___ regions contain only old stars. The younger ones have ended their lives. And the ___ regions contain both young and old stars and the young, more luminous ones dominate the light.
red, blue
Based on information about the Milky Way and Andromeda...
the collision stars just after 3 billion years in the move and is complete a bit after 5 billion years
Orion nebula: What is the trapezium?
Four young stars whose stellar winds and energy input significantly affect the nebula
Which of the following main-sequence turnoffs indicates the oldest globular cluster?
G2
Gas is added to the interstellar medium by supernovae and by planetary nebulae like this one. From what you remember of stellar evolution, what kind of gas would you expect that to be?
Gas that has a mix of heavier elements in it, such as carbon, oxygen, silicon, iron, etc.
What causes the red glow in the Helix Nebula?
Hydrogen gas heated by central remnant
Crab nebula: The colors are produced by the same elements as before - hydrogen, oxygen, sulfur. But what about that blueish haze in the middle?
It is produced by accelerated electrons.
What is the Planck length and how small is it?
Its the smallest unit of fabric of the space itself- and it is 10^-35m
There's something at the Galaxy's center that is very dark and is under 17 light-hours in radius. How could you figure out the mass of such an object?
Kepler's third law
Can you tell me which cluster of the following is the oldest?
M67
What type of stars does the bar contain?
old, cool stars that glow redder
Our whole Galaxy is about __ times larger in size.
10,000
Crab nebula: What year did people on Earth see this star explode?
1054
When do you start to get down to the size of red blood cells in the scale of the universe?
10^-5m
When do you start to get down to the size of hydrogen atoms in the scale of the universe?
10^-9m
How big are the nebulae on the scale?
10^17m
The Virgo Cluster is about __ in size
10^24m (1,000 times larger than the Milky Way)
What scales do we see distant filaments and voids on?
10^25m
Cassiopeia A: The blast wave from the supernova is moving at...
16,000,000 kilometers per hour
The supermassive blackhole at the center of the galaxy is...
26,000 light-years away
There are __ areas this size needed to cover the whole sky.
30 million
Cassiopeia A: How long ago did this supernova occur?
340 years ago
Crab nebula: What is the source of this magnetic field? What is at the very center?
A neutron star
Do you remember what gets left behind in the middle of a planetary nebula?
A white dwarf
What are possible reasons that galaxies differ in form?
A. Pre-galactic clouds have different densities B. Pre-galactic clouds have different rotation rates C. Galaxies collide with one another, creating different types D. All of the above All of the above
Based on the HR diagram I showed you, how old is this cluster?
About 8 billion years old
Cassiopeia A: What elements are in the supernova remnant?
All of the above (Oxygen, sulfur, hydrogen, nitrogen)
Why do you suppose this nebula has a certain symmetry?
Bipolar jets are creating matching shapes on both sides.
What do spiral arms contain?
The hottest, newest stars
When galaxies collide...
Their mutual gravitation will greatly distort each galaxy Gas and dust from the two galaxies collide and stars form.) B&C
How is the donut-shape of the Helix nebula caused by our line-of-sight?
There are multiple disks of dust and gas at different angles.
How would you describe the distribution of galaxies in your Local Group?
There are two big galaxies, and then the dwarfs seem to be clustered around them
What can we say about stars that contain relatively few amounts of heavy elements?
They are older than stars with more heavy elements.
What is true of irregular galaxies?
They have no defined shape or structure.
The amount of light given off during a Type 1 supernova is very similar to that of a type 2 core collapse supernova. What about their spectra? What are these different types of explosions made of?
They should be similar, but only type 2 supernovae have hydrogen lines
When we look at the farthest galaxies in the Hubble Ultra Deep Field here, we see their light from:
about 12 or 13 billion years ago
The main-sequence turnoff of a star cluster tells us the cluster's
age
It said that ellipticals can be small as well. Were those dwarf galaxies we saw in the Local Group ellipticals ? The galaxies near Andromeda looked like:
an oval-shaped haze
V838 Monocerotis, Supernova Remnant. The gas and dust around the star is...
being illuminated up by the star behind it
What color are the star clusters in the spiral arms and what does that mean?
blue and that means they have just formed recently
What kind of galaxies are the largest in our Universe?
elliptical
What other populations of stars we've seen so far are relatively old?
globular clusters
The open clusters were a population of relatively young stars, so where would you expect to see them from the Milky Way?
in the disk
