Douglas Middendorf's Quiz

What does our galaxy look like?

Spiral disk.

How do stars orbit in our galaxy?

Around a center point, and up and down.

How is gas recycled in our galaxy?

gas is recycled through the star-gas-star cycle.

Where do stars tend to form in our galaxy?

In nebulas

Who is Andrea M. Ghez?

An American astronomer and professor in the Department of Physics and Astronomy at UCLA

What is the name of our galaxy?

The Milky way.

What is the ratio between the diameter and the thickness of the galactic disc?

100 : 1

Is our galaxy rotating?

Yes.

Can our galaxy be seen at night far from cities?

Yes.

Why do we need satellites to detect gamma rays from our galaxy?

There is less interference outside our atmosphere.

Quiz

1. What do halo stars tell us about our galaxy's history?
2. How did our galaxy form?
3. What lies in the center of our galaxy?
4. What are the three major types of galaxies?
5. How are galaxies grouped together?
6. How do we measure the distances to galaxies?
7. What is Hubble's law?
8. How do distance measurements tell us the age of the universe?
9. Name a galaxy nearby.
10. What is the mass of the black hole in the center of the galaxy?

04/30/2013 Quiz

1. What does our galaxy look like? Our galaxy consists of a flat disk with spiral arms surrounding a central bulge, with a roughly spherical halo surrounding everything.
2. How do stars orbit in our galaxy? Disk stars orbit the galaxy's center in orderly circles that all go in the same direction.  Halo stars swoop high above and below the disk on randomly oriented orbits.
3. How is gas recycled in our galaxy? Through the star gas star cycle.
4. Where do stars tend to form in our galaxy? Orion Nebula
5. Who is Andrea M. Ghez? She's discovered many stars in a highly elliptical orbit around the huge black hole at the center of our galaxy.
6. What is the name of our galaxy? Milky Way
7. What is the ratio between the diameter and the thickness of the galactic disc? 100000 : 1000
8. Is our galaxy rotating? Yes
9. Can our galaxy be seen at night far from cities? Yes
10. Why do we need satellites to detect gamma rays from our galaxy? Because our ozone layer protects us from the gamma rays, making them impossible to detect.

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Quiz 4/29/2013

1. What does our galaxy look like?
Our galaxy consists of a flat disk with spiral arms surrounding a central bulge, with a roughly spherical halo surrounding everything.
2. How do stars orbit in our galaxy?
Disk stars orbit the galaxy's center in orderly circles that all go in the same direction, bobbing slightly up and down as they orbit. Halo stars swoop high above and below the disk on randomly oriented orbits.
3. How is gas recycled in our galaxy?
Through the star-gas-star cycle, atomic hydrogen clouds, molecular clouds, star formation, nuclear fusion in stars, returning gas, hot bubbles.
4. Where do stars tend to form in our galaxy?
Stars tend to form in the Orion Nebula.
5. Who is Andrea M. Ghez?
Andrea M. Ghez is a professor in the Department of Physics and Astronomy at UCLA. She's discovered many stars in a highly elliptical orbit around the huge black hole at the center of our galaxy.
6.What is the name of our galaxy?
The Milky Way Galaxy
7. What is the ratio between the diameter and the thickness of the galactic disc?
100000 : 1000
8. Is our galaxy rotating?
Yes, our galaxy is rotating.
9. Can our galaxy be seen at night far from cities?
Yes it can.
10. Why do we need satellites to detect gamma rays from our galaxy?
We need satellites because our ozone layer protects us from the gamma rays, making them impossible to detect.

4-27-13 quiz

Vinnie Caringella

Astronomy

4-27-13

Quiz

1. Our galaxy consists of a disk of stars and gas, with a bulge of stars at the center of the disk, surrounded by a large spherical halo.

2. Stars in the disk orbit in circles going in the same direction with a little up and down motion.

3. Gas from dying stars mixes new elements into the interstellar medium, which slowly cools, making the molecular clouds where stars come from.

4. Active star-forming regions contain molecular clouds, hot stars

5. An American astronomer and professor in the Department of Physics and Astronomy at UCLA.

6. The Milky Way

7. About 100 times as great as the thickness.

8. Yes

9. No, there is too much light around.

10. short wavelength and lots of energy.

In Midwest, Drought Abruptly Gives Way to Flood - NYTimes.com

In Midwest, Drought Abruptly Gives Way to Flood - NYTimes.com:

"CHICAGO — The nation’s midsection, which was for months parched by severe drought, suddenly finds itself contending with the opposite: severe flooding that has forced evacuations, slowed commercial barge traffic down the Mississippi River and left farmers with submerged fields during a crucial planting time."

'via Blog this'

Laura Soto's Quiz

Laura Soto
Tuesday April 23, 2013
Quiz

What is a black hole?
-An object that has a gravitational field that light cannot escape.
What would it be like to visit a black hole?
-You can orbit a black hole like any other object of the same mass-black holes don’t suck! Near the event
horizon time slows down and tidal forces are very strong.
Do black holes really exist?
-Yes
What causes gamma ray bursts?
-A collapsing star.
What is in the center of the Milky Way?
-A large black hole.
What is the mass of the object in the center of our galaxy?
-4 million solar masses.
Who was John Michell?
-An English geologist and philosopher.
Who was Pierre-Simon Laplace?
-A French mathematician and astronomer
Who was Karl Schwarzschild?
-A German physicist
What is the Schwarzschild radius of Earth?
-8.869 mm

Thursday, April 25, 2013
Quiz

What does our galaxy look like?
-Our galaxy consists of a disk of stars and gas, with a bulge of stars at the center of the disk, surrounded
by a large spherical halo.
How do stars orbit in our galaxy?
-Stars in the disk orbit in circles going in the same direction with a little up and down motion.
How is gas recycled in our galaxy?
-Gas from dying stars mixes new elements into the interstellar medium, which slowly cools, making the
molecular clouds where stars come from.
Where do stars tend to form in our galaxy?
-Active star-forming regions contain molecular clouds, hot stars, and ionization mubulae.
Who is Andrea M. Ghez?
-Andrea Mia Ghez (born June 16, 1965) is an American astronomer and professor in the Department of
Physics and Astronomy at UCLA.
What is the name of our galaxy?
-The Milky Way
What is the ratio between the diameter and the thickness of the galactic disc?
-the diameter is about 100 times as great as the thickness.
Is our galaxy rotating?
-Yes

Can our galaxy be seen at night far from cities?
-No, there is too much light around.
Why do we need satellites to detect gamma rays from our galaxy?
-Because they have a short wavelength and lots of energy.

04/25/2013 Quiz

1. What is a black hole? An object that has a gravitational field that light can not escape.
2. What  would it be like to visit a black hole? It would be very interesting.
3. Do black holes really exist? Yes
4. What causes gamma ray bursts? A collapsing star.
5. What is in the center of the milky way? A large black hole. 
6. What is the mass of the object in the center of our galaxy? 4 million solar masses.
7. Who was John Michell? An English geologist and philosopher.
8. Who was Pierre-Simon Laplace? A french mathematician and astronomer
9. Who was Karl Schwarzschild? A German physicist 
10. What is the Schwarzschild radius of Earth? 8.869 mm

Hint: Search for black holes in Wikipedia

04/17/2013 Quiz

1. What is a white dwarf? A white dwarf is the hot, compact corpses of low-mass stars, typically with a mass similar to that of the Sun compressed to a volume the size of Earth.
2. What can happen to a white dwarf in a close binary system? A white dwarf in a close binary system can gradually gain mass if its companion is a main-sequence or giant star.
3. What is a neutron star? A neutron star is a ball of neutrons just a few kilometers in radius but with a mass like that of the Sun.
4. How were neutron stars discovered? Neutron stars can spin rapidly and emit beams of radiation along their magnetic poles, which we detect as pulses of radiation if the beams sweep by Earth
5. What can happen to a neutron star in a close binary system? They can burst back to life.
6. Who was Jocelyn Bell? She discovered a rapidly rotating neutron star. 
7. Does she have a Nobel Prize? No
8. What were called then little green men?   The signal was pulsing with great regularity and temporarily dubbed it the Little Green Men 1.
9. Who was her thesis adviser? Antony Hewish
10. Did the thesis adviser get a Nobel Prize? Yes

Quiz

1. What does our galaxy look like?
2. How do stars orbit in our galaxy?
3. How is gas recycled in our galaxy?
4. Where do stars tend to form in our galaxy?
5. Who is Andrea M. Ghez?
6. What is the name of our galaxy?
7. What is the ratio between the diameter and the thickness of the galactic disc?
8. Is our galaxy rotating?
9. Can our galaxy be seen at night far from cities?
10. Why do we need satellites to detect gamma rays from our galaxy?

Hint: Check Wikipedia for Andrea M. Ghez

4-24-13

Vinnie Caringella
4-24-13
Astronomy

QUIZ

1. An object that has a gravitational field that light can not escape.

2. YES, It would be interesting

3. YES

4. A collapsing star.

5. A massive black hole.

6. 4 million solar masses.

7. An English geologist and philosopher. 

8. A French mathematician and astronomer.

9. A German physicist.

10. 8.869 mm.

Inside a Black Hole

Douglas Middendorf's Quiz

What is a black hole?

An object that has a gravitational field that light can not escape.

What  would it be like to visit a black hole?

It would be interesting:  http://www.youtube.com/watch?v=3pAnRKD4raY

Do black holes really exist?

Almost certainly.

What causes gamma ray bursts?

A collapsing star.

What is in the center of the milky way?

A massive black hole.

What is the mass of the object in the center of our galaxy?

It is on the order of 4 million solar masses.

Who was John Michell? 

An English geologist and philosopher. 

Who was Pierre-Simon Laplace?

A French mathematician and astronomer.

Who was Karl Schwarzschild?

A German physicist.

What is the Schwarzschild radius of Earth?

8.869 mm.

Douglas Middendorf

Last Thursday we watched Alex Filippenko's video on black holes. In the video he discussed how black holes are formed, their properties and the effects that they have on light and stellar bodies. He also went over the terms singularity, event horizon, jet, accretion disk and photon sphere.

Sylvia Todd, Science Star, Tinkers With the Idea of Growing Up - NYTimes.com

Sylvia Todd, Science Star, Tinkers With the Idea of Growing Up - NYTimes.com:

"“I love stars,” she said. “I’ve always wanted to be an astronaut, or an aeronautical engineer.”"

'via Blog this'

Quiz

1. What is a black hole?
2. What  would it be like to visit a black hole?
3. Do black holes really exist?
4. What causes gamma ray bursts?
5. What is in the center of the milky way?
6. What is the mass of the object in the center of our galaxy?
7. Who was John Michell? 
8. Who was Pierre-Simon Laplace?
9. Who was Karl Schwarzschild?
10. What is the Schwarzschild radius of Earth?

Hint: Search for black holes in Wikipedia

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2 Good Places to Live, 1,200 Light-Years Away - NYTimes.com

2 Good Places to Live, 1,200 Light-Years Away - NYTimes.com:

 "Nobody will probably ever know if anything lives on these planets, and the odds are that humans will travel there only in their faster-than-light dreams, but the news has sent astronomers into heavenly raptures. William Borucki of NASA’s Ames Research Center, head of the Kepler project, described one of the new worlds as the best site for Life Out There yet found in Kepler’s four-years-and-counting search for other Earths in the stars. He treated his team to pizza and beer on his own dime to celebrate the find (this being the age of sequestration). “It’s a big deal,” he said."

"Alan Boss, a planetary expert at the Carnegie Institution of Washington and a member of the Kepler team, called the new results the capstone of the Kepler mission. “I would argue,” he said in an e-mail, “that if this was all that we learned from Kepler, that the cost of this mission was justified.”"

'via Blog this'

Heavy Rains in Chicago Area Cause Flooding and Road Closures: Scientific American

Heavy Rains in Chicago Area Cause Flooding and Road Closures: Scientific American:

"Heavy rains and flooding brought havoc to the Chicago area on Thursday, shutting major expressways, delaying commuter trains for hours, cancelling flights, flooding basements and closing dozens of suburban schools."

'via Blog this'

Today's Class

Due to the flood, I showed Alex Filippenko's video on Black Holes, and Gamma Ray Bursts. Those of you in attendance, please write a description of Alex's lectures.

Next Tuesday we will finish Chapter 13.

Douglas Middendorf's Quiz

What is a white dwarf?

A small very dense star that is typically the size of a planet.

What can happen to a white dwarf in a close binary system?

It can pull matter away from another star that is less dense.

What is a neutron star?

An extremely dense, compact star composed primarily of neutrons, especially thecollapsed core of a supernova.

How were neutron stars discovered?

They were discovered by the pulses of radio waves they emitted.

What can happen to a neutron star in a close binary system?

The same that happens with a neutron star, the falling matter will form an accretion disk.

Who was Jocelyn Bell?

The woman who helped discover pulsars.

Does she have a Nobel Prize?

No.

What were called then little green men?

Whatever was emitting the pulses.

Who was her thesis adviser?

Antony Hewish

Did the thesis adviser get a Nobel Prize?

Yes.

4-17-13

Vinnie Caringella

Astronomy

4-17-13

Quiz

1. A white dwarf is the hot, compact corpses of low-mass stars

2. A close binary system can gradually gain mass if its companion is a main-sequence or giant star.

3. A neutron star is a ball of neutrons just a few kilometers in radius but with a mass like that of the Sun.

4. Neutron stars can spin rapidly and emit beams of radiation along their magnetic poles, which we detect as pulses of radiation if the beams sweep by Earth.

5. Swirling accretion disk around the neutron star, but much hotter and denser than an accretion disk around a white dwarf. X-ray binaries.

6. Jocelyn Bell discovered a rapidly rotating neutron star.

7 NO!!

8. She discovered a bit of "scruff" on her chart-recorder papers that tracked across the sky with the stars. The signal was pulsing with great regularity and temporarily dubbed it the Little Green Men

9.  Antony Hewish.

10. YES

Fish’s DNA May Explain How Fins Turned to Feet - NYTimes.com

Fish’s DNA May Explain How Fins Turned to Feet - NYTimes.com:

 "Another helpful preadaptation is a snippet of DNA that enhances the activity of the genes that drive the formation of limbs in the embryo. The Amemiya team focused on the enhancer DNA sequence because it occurred in the coelacanth and animals but not in ordinary fish. They then inserted the coelacanth enhancer DNA into mice. “It lit up right away and made an almost normal limb,” said Neil Shubin, meaning that the coelacanth gene enhancer successfully encouraged the mouse genes to make a limb. Dr. Shubin, a member of the team, is a paleontologist at the University of Chicago."

'via Blog this'

Olivia Thomas' Quiz 4/17/2013

1. What is a white dwarf?

A white dwarf is the hot, compact corpses of low-mass stars, typically with a mass similar to that of the Sun compressed to a volume the size of Earth.

2. What can happen to a white dwarf in a close binary system?

A white dwarf in a close binary system can gradually gain mass if its companion is a main-sequence or giant star. Also, in a close binary system, gas from a companion star can spill toward a white dwarf, forming a swirling accretion disk around it.

3. What is a neutron star?

A neutron star is a ball of neutrons just a few kilometers in radius but with a mass like that of the Sun.

4. How were neutron stars discovered?

Neutron stars can spin rapidly and emit beams of radiation along their magnetic poles, which we detect as pulses of radiation if the beams sweep by Earth.

5. What can happen to a neutron star in a close binary system?

They can brilliantly burst back to life, can create a hot, swirling accretion disk around the neutron star, but much hotter and denser than an accretion disk around a white dwarf. X-ray binaries.

6. Who was Jocelyn Bell?

Jocelyn Bell discovered a rapidly rotating neutron star. She served two years as the President of the Institute of Physics and  is currently a visiting professor of astrophysics at the University of Oxford and a fellow of Mansfield College.

7. Does she have a Nobel Prize?

No, Jocelyn Bell did not receive a Nobel Prize.

8. What were called then little green men?

She discovered a bit of "scruff" on her chart-recorder papers that tracked across the sky with the stars. The signal was pulsing with great regularity and temporarily dubbed it the Little Green Men 1.

9. Who was her thesis adviser?

Her thesis adviser was Antony Hewish.

10. Did the thesis adviser get a Nobel Prize?

Yes, Antony Hewish did receive a Nobel Prize.

Quiz 04/16/2013

1. What are the life stages of a high-mass star? They live short lives, rapidly fusing its core hydrogen into helium.
2. How do high-mass stars make the elements necessary for life? They create these elements through helium capture.
3. How does a high-mass star die? When gravity overcomes degeneracy pressure in the iron core, the core collapses into a ball of neutrons and the star explodes in a super nova.
4. How does a star's mass determine its life story? Stars born with masses less than 8M Sun follow life stages similar to those of our Sun
5. How are the lives of stars with close companions different? Stars in close binary systems can exchange mass with each other, altering their life histories. 
6. When did Supernova 1987A explode? February 23, 1987
7. In which hemisphere was it seen? The southern hemisphere.
8. Which civilization saw Supernova 1054? Chinese
9. What happened in the Crab Nebula 959 years ago? Supernova 1054 exploded
10. Are neutrinos produced in a supernova explosion? Yes

Quiz

1. What is a white dwarf?
2. What can happen to a white dwarf in a close binary system?
3. What is a neutron star?
4. How were neutron stars discovered?
5. What can happen to a neutron star in a close binary system?
6. Who was Jocelyn Bell?
7. Does she have a Nobel Prize?
8. What were called then little green men?
9. Who was her thesis adviser?
10. Did the thesis adviser get a Nobel Prize?

Douglas Middendorf's Quiz

How do stars form?

Stars form from massive clouds of gas and dust.

How massive are newborn stars?

They can be gigantic, the largest discovered protostar is about 300 times the size of our Solar System.

What are the life stages of a low-mass star?

gas and dust, main sequence,red giant, planetary nebula, white dwarf or supernova.

How does a low-mass star die?

by supernova or white dwarf.

Do stars produce calcium?

Yes.

Have we seen stars being born?

kind of, there are pictures of stellar nurseries. 

What is a planetary nebula?

A ring-shaped nebula formed by an expanding shell of gas around an aging star.

Are new stars being born in the Orion nebula?

Yes.

What is the mass range of most stars?

0.1 to 20 solar masses.

How does the law of angular momentum apply to star formation?  

Stars form by collecting dust and gas, as they condense they spin very fast and keep their angular momentum throughout their life.

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4-15-13 Quiz

Vinnie Caringella

Astronomy

4-15-13

Quiz

1. A high-mass star lives a short life, rapidly fusing its core hydrogen into helium via the CNO cycle.

2. They create the elements through helium capture.

3. When gravity overcomes degeneracy pressure in the iron core, the core collapses into a ball of neutrons and the star explodes in a super nova.

4. Stars born with masses less than 8M Sun follow life stages similar to those of our Sun

5. Stars in close binary systems can exchange mass with each other, altering their life histories.

6. February 23, 1987.

7. southern hemisphere.

8. The Chinese.

9 Supernova 1054 exploded.

10. YES!

Olivia Thomas' Quiz 4/16/2013

1. What are the life stages of a high-mass star?

A high-mass star lives a short life, rapidly fusing its core hydrogen into helium via the CNO cycle. Near the end of its life, a high-mass star expands to become a supergiant as fusion proceeds furiously in its core and surrounding shells.

2. How do high-mass stars make the elements necessary for life?

They create the elements through helium capture. The core of a high-mass star eventually becomes hot enough for fusion to produce the elemts of which we and Earth are made.

3. How does a high-mass star die?

When gravity overcomes degeneracy pressure in the iron core, the core collapses into a ball of neutrons and the star explodes in a super nova.

4. How does a star's mass determine its life story?

Stars born with masses less than 8M Sun follow life stages similar to those of our Sun, while more massive stars live short but brilliant lives and die in supernova explosions.

5. How are the lives of stars with close companions different?

Stars in close binary systems can exchange mass with each other, altering their life histories.

6. When did Supernova 1987A explode?

The light reached Earth on February 23, 1987.

7. In which hemisphere was it seen?

It could be seen from the southern hemisphere.

8. Which civilization saw Supernova 1054?

The Chinese saw Supernova 1054.

9. What happened in the Crab Nebular 959 years ago?

Supernova 1054 exploded.

10. Are neutrinos produced in a supernova explosion?

Yes neutrinos are produced in a supernova explosion.

Quiz

1. What are the life stages of a high-mass star?
2. How do high-mass stars make the elements necessary for life?
3. How does a high-mass star die?
4. How does a star's mass determine its life story?
5. How are the lives of stars with close companions different?
6. When did Supernova 1987A explode?
7. In which hemisphere was it seen?
8. Which civilization saw Supernova 1054?
9. What happened in the Crab Nebula 959 years ago?
10. Are neutrinos produced in a supernova explosion?

Hint: Check SN1987A, SN1054, and the Crab Nebula in Wikipedia.

04/11/13 Quiz

1. How do stars form? A star is born when gravity causes a cloud of interstellar gas to contract to the point at which the central object becomes hot enough to sustain nuclear fusion in its core.
2. How massive are newborn stars? 300m Sun to 0.08m Sun.
3. What are the life stages of a low-mass star? Stars go through a main-sequence stage, a red giant stage, and then goes through it's last gasps.
4. How does a low-mass star die? The low-mass star will eject its outer layers into space, creating a huge shell of gas expanding away from the inert carbon core.
5. Do stars produce calcium? Yes
6. Have we seen stars being born? Yes
7. What is a planetary nebula? Emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their lives.
8. Are new stars being born in the Orion nebula? Yes
9. What is the mass range of most stars? Sun to 0.08m Sun.
10. How does the law of angular momentum apply to star formation? Conservation of angular momentum ensures that protostars rotate rapidly.

04/09/13 Quiz

1. How do we measure stellar masses? We can measure the mass by the spectral type.
2. What are giants, supergiants, and white dwarfs? Giants and supergiants are stars that are nearing the ends of their lives.  White dwarfs stars are the cooling embers of stars that have exhausted their fuel for nuclear fusion.
3. What are the two types of star clusters? Modest sized open clusters and densely packed globular clusters. 
4. How do we measure the age of a star cluster? By plotting their stars in an H-R diagram.
5. Do we know any star cluster 14 billion years old, or older? No
6. Which star has a longer life, small mass star, or big mass star? Small mass star.
7. Which star is hotter, small mass star, or big mass star? High mass stars.
8. Which star is bluer, small mass star, or big mass star? Big mass stars
9. Which star is closer, the Sun, or Proxima Centaurus? The Sun
10. What is the age of the Universe? 13.77 billion years old

14 Billion Year Old, or Older Cluster

In a previous class I told you that if we had a 14 billion year old cluster or older, we will have a problem. The universe is less old than that. We cannot have an object inside the universe 14 billion years old or older. If by any chance one is discovered, we will have to change our Big Bang model.

Megan DeCianni's Quiz

 in a cold, dense molecular cloud. As the cloud fragment collapses
under gravity, it becomes a protostar.

2. greater than about 300M Sun

3. H fusion in core (main sequence)
H fusion in shell around contracting core (red giant)
He fusion in core (horizontal branch)
Double shell-fusion (red giant)

4. ejection of H and He in a planetary nebula

5. yes

6. yes

7. emission nebula consisting of an expanding glowing shell of ionized
gas ejected during the asymptotic giant branch phase of certain types
of stars late in their lives

8. yes

9. stars very in size. 300M Sun- 0.08 M Sun

10. ensures that protostars rotate rapidly

4-10-13

Vinnie Caringella

Astronomy

4-10-13

Quiz 19

1. A star is born when gravity causes a cloud of interstellar gas to contract to the point at which the central object becomes hot enough to sustain nuclear fusion in its core.

2. 300M Sun to 0.08M Sun.

3. Stars go through a main-sequence stage, a red giant stage, and then goes through it's last gasps.

4. The low-mass star will eject its outer layers into space, creating a huge shell of gas expanding away from the inert carbon core.

5. Yes

6.Yes

7. A planetary nebular is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their lives.

8. Yes

9. Sun to 0.08M Sun.

10. Conservation of angular momentum ensures that protostars rotate rapidly.

Planetary Nebula

On p.344 of The Essential Cosmic Perspective,  you can read:

"When it dies, the Sun will eject its outer layers into space as a planetary nebula, leaving its exposed core behind as a white dwarf"

Olivia Thomas' Quiz

1. How do stars form?

A star is born when gravity causes a cloud of interstellar gas to contract to the point at which the central object becomes hot enough to sustain nuclear fusion in its core.

2. How massive are newborn stars?

Stars vary in size; from 300M Sun to 0.08M Sun.

3. What are the life stages of a low-mass star?

Stars go through a main-sequence stage, a red giant stage, and then goes through it's last gasps.

4. How does a low-mass star die?

The low-mass star will eject its outer layers into space, creating a huge shell of gas expanding away from the inert carbon core. The exposed core will emit intense ultraviolet radiation. The radiation will ionize the gas in the expanding shell making it glow brightly as a planetary nebula.

5. Do stars produce calcium?

Yes, stars produce calcium.

6. Have we seen stars being born?

Yes, we have seen stars being born.

7. What is a planetary nebula?

A planetary nebular is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their lives.

8. Are new stars being born in the Orion nebula?

Yes, the Orion nebula is a stellar nursery.

9. What is the mass range of most stars?

Stars vary in size; from 300M Sun to 0.08M Sun.

10. How does the law of angular momentum apply to star formation?

Conservation of angular momentum ensures that protostars rotate rapidly and are surrounded by spinning disks of gas.

4-9-13 quiz

Vinnie Caringella

Astronomy

4-9-13

Quiz

1. A star's position along the main sequence is closely related to its mass.  We can estimate a star's mass just by knowing it's spectral type.

2. Giants and supergiants are stars that are nearing the ends of their lives. They are cooler but much more luminous than the Sun. They place in the upper right of the main sequence in an H-R diagram. White dwarfs stars are the cooling embers of stars that have exhausted their fuel for nuclear fusion.

3.There are modest-sized open clusters and densely packed globular clusters. The two types differ in how densely they're packed with stars, locations, and ages.

4. We can determine their ages by plotting their stars in an H-R diagram.The age of a star cluster approximately equals the hydrogen core-fusion lifetime of the most massive main-sequence stars remaining within it.

5. No we do not know any star clusters older than 14 billion years old.

6.A small mass star is going to have a longer life compared to a big mass star. More massive stars live much shorter lives because they fuse hydrogen at a much greater rate.

7. High mass stars are hotter than small mass stars.

8.Big mass stars are bluer than small mass stars.

9. The sun is closer.

10. 13.77 billion years old.