Reach for the Stars B

[anandymous]

1. correct 2. sorta its when the less massive star is more evolved, u are right that its due to mass transfer Your Turn!

Alright.

Spectroscopy

1. What does the width of a spectral emission or absorption line show?

2. How can someone conclude if a system is binary through spectroscopy?

3. Where does the H-alpha line occur?

1. It tells the amount of that substance? 2. They will see a cycle of the 2 star's spectra? 3. 656.28 nanometers

[Locoholic]

1. It tells the amount of that substance? 2. They will see a cycle of the 2 star's spectra? 3. 656.28 nanometers

1. It tells the object's speed and any stellar wind present. I don't fully understand this either--took notes on this a while ago. But I feel like it has something to do with Doppler broadening. Will look into it some more. 2. Well yes, but a cycle of what? If the lines grow & fade in strength periodically, then one can conclude a binary system to be present. 3. Should have specified the question a bit. You are right, but I really meant to ask the physical location of H-alpha occurances. In that case it would be where hydrogen is being ionized. Your turn!

[anandymous]

1. It tells the amount of that substance? 2. They will see a cycle of the 2 star's spectra? 3. 656.28 nanometers

1. It tells the object's speed and any stellar wind present. I don't fully understand this either--took notes on this a while ago. But I feel like it has something to do with Doppler broadening. Will look into it some more. 2. Well yes, but a cycle of what? If the lines grow & fade in strength periodically, then one can conclude a binary system to be present. 3. Should have specified the question a bit. You are right, but I really meant to ask the physical location of H-alpha occurances. In that case it would be where hydrogen is being ionized. Your turn!

Yeaa I need to study spectroscopy pretty bad...
Nebulae!!!
1. What broader type of nebulae are planetary nebulae?
2. Explain the type of nebulae that is the answer to #1.
3. Give an explanation of how planetary nebula can be elliptical.

[Locoholic]

Yeaa I need to study spectroscopy pretty bad...
Nebulae!!!
1. What broader type of nebulae are planetary nebulae?
2. Explain the type of nebulae that is the answer to #1.
3. Give an explanation of how planetary nebula can be elliptical.

1. Emission? All I know is that emission nebulae have a lot of star formation. 2. It is a nebula that shines with its own light. It's a cloud of hot, ionized gas. It takes energy from UV sources. It's usually red because the predominant emission line of hydrogen is red. They are usually sites of recent & ongoing star formation. 3. Not sure, but maybe it's that newly forming stars distort the shape of the nebula. Or maybe it's because it expands.

[anandymous]

Yeaa I need to study spectroscopy pretty bad...
Nebulae!!!
1. What broader type of nebulae are planetary nebulae?
2. Explain the type of nebulae that is the answer to #1.
3. Give an explanation of how planetary nebula can be elliptical.

1. Emission? All I know is that emission nebulae have a lot of star formation. 2. It is a nebula that shines with its own light. It's a cloud of hot, ionized gas. It takes energy from UV sources. It's usually red because the predominant emission line of hydrogen is red. They are usually sites of recent & ongoing star formation. 3. Not sure, but maybe it's that newly forming stars distort the shape of the nebula. Or maybe it's because it expands.

1. correct 2. correct 3. Its when the nebula forms from a binary system, they send more material on the sides of the stars (I think, don't quote me). Also this is not the only answer, there are a few other ways. Your turn!

[Locoholic]

Stellar Evolution

1. The helium flash occurs between what two stellar evolutionary phases?

2. When does the alpha-process occur in relation to the triple-alpha process?

3. What is the minimum mass required for nuclear fusion to occur?

[fishbutt327]

Stellar Evolution

1. The helium flash occurs between what two stellar evolutionary phases?

2. When does the alpha-process occur in relation to the triple-alpha process?

3. What is the minimum mass required for nuclear fusion to occur?

1. red giant branch and asymptotic giant branch 2. after the triple alpha process has accumulated enough carbon then the alpha process can start 3. 0.08 solar masses

[Locoholic]

Stellar Evolution

1. The helium flash occurs between what two stellar evolutionary phases?

2. When does the alpha-process occur in relation to the triple-alpha process?

3. What is the minimum mass required for nuclear fusion to occur?

1. red giant branch and asymptotic giant branch 2. after the triple alpha process has accumulated enough carbon then the alpha process can start 3. 0.08 solar masses

1. Red Giant and Horizontal branches. AGB comes later. 2. Correct! 3. Correct! Your turn!

[Locoholic]

Ok I want to revive this thread so...

1. Which Hubble type of galaxy contains the oldest stars? What is the class name given to these stars? Which type contains the youngest stars? What is the class name given to these stars? What population of stars is currently theoretical, given to stars older than those that experimentally exist?

2. Identify the DSO shown below. Give all appropriate names for it. How far away is this DSO? What is so significant about this DSO?


3. Star A has an apparent magnitude of 2.5 and star B has an apparent magnitude of 7.5. Which star(s) can be seen with the naked eye? What is the approximate limit for a star to be seen with the naked eye? How many times more luminous is star A than star B? Assuming these stars have the same temperature, what is the size of star A compared to star B? Show all of your work.

[AstroKing]

1.

Click to Show Answer

Oldest Stars: Elliptical Galaxy, Youngest Stars: Spiral Galaxy (specifically spiral arms), IDK which class name, Population II stars

2.

Click to Show Answer

Centaurus A, NGC 5128, 13.05 million lightyears away, prominent dust lane, a merger of two smaller galaxies, active starburst galaxy with AGN

3.

Click to Show Answer

Star A can be seen with the naked eye, about 6 to 7 varies based on light pollution, Star A is 100 times more luminous because they have a difference of 5 (7.5-2.5 = 5), and an increase in magnitude 5 is an increase of 100, so it's 100, Last one you set up two equations L1= R1^2 x T1^4, L2 = R2^2 x T2^4, we can then divide both equations to find the change in the radius, since we know the difference in luminosity and the temperature is the same. Since the temperature is the same then when we divide them it is going to stay constant, so now we have L1 = R1^2, and L2 = R2^2, now we know that the luminosity of the first star is 100 times the second star, we can plug that into the equation to get 100 = R1^2 and 1 = R2^2, now when you divide you get 100 = R1^2/R2^2, square rooting both sides we get R1/R2 = 10, this is the ratio of the radiuses which correlates to the size of the star, so our answer is 10  

Thank you so much Locoholic for these questions, I really enjoyed them a lot especially the last question. The last one was very intriguing and interesting and the method to solve it was very fun. I didn't see much problems like the last one. Also, can you please share me what the class names were for the first question? .

This was really fun, and this is my first post on Question Marathons, and since this was really fun, I'm going to post more!