Reach for the Stars B

[anandymous]

It's time for some math...

1. What is the maximum wavelength emitted by a blackbody with a temperature of 4000 K?

2. RR Lyrae stars have approximately the same absolute magnitude of +0.5 and are common in globular clusters. An RR Lyrae star in one globular cluster has an apparent magnitude of 16.5. What is the distance to the cluster in light years?

3. How long does it take light to travel to us from an object with a parallax of 0.042 arcseconds?

I'll accept rounded answers.

1. 725 nanometers
2. 51667.518 light years
3. 77.619 years

[Locoholic]

It's time for some math...

1. What is the maximum wavelength emitted by a blackbody with a temperature of 4000 K?

2. RR Lyrae stars have approximately the same absolute magnitude of +0.5 and are common in globular clusters. An RR Lyrae star in one globular cluster has an apparent magnitude of 16.5. What is the distance to the cluster in light years?

3. How long does it take light to travel to us from an object with a parallax of 0.042 arcseconds?

I'll accept rounded answers.

1. 725 nanometers
2. 51667.518 light years
3. 77.619 years

All correct, your turn!

[anandymous]

This is the farthest and oldest known galaxy to humans.
1. What is this galaxy?
2. Why is this galaxy the oldest known galaxy (be specific)?
3. Why do we have a limited time to study this galaxy?

[IHateClouds]

This is the farthest and oldest known galaxy to humans.
1. What is this galaxy?
2. Why is this galaxy the oldest known galaxy (be specific)?
3. Why do we have a limited time to study this galaxy?

1. Gn-z11


2 Its 13.4 billion years old, existing 4million years after the big bang? not really sure what you meant
3. im gonna guess due to the expnsion of the universe, its getting farther from us so eventually we won't be able to see it anymore

[anandymous]

This is the farthest and oldest known galaxy to humans.
1. What is this galaxy?
2. Why is this galaxy the oldest known galaxy (be specific)?
3. Why do we have a limited time to study this galaxy?

1. Gn-z11


2 Its 13.4 billion years old, existing 4million years after the big bang? not really sure what you meant
3. im gonna guess due to the expnsion of the universe, its getting farther from us so eventually we won't be able to see it anymore

1. correct
2. Sorry for the weird wording. Its the oldest known galaxy BECAUSE it is the farthest known galaxy, it takes light time to travel to Earth so we are seeing Gn-z11 so many years in the past.
3. U r right that it is getting father away, but I was looking for that it would be redshifted so much it would be undetectable.
Your turn!

[IHateClouds]

1. correct
2. Sorry for the weird wording. Its the oldest known galaxy BECAUSE it is the farthest known galaxy, it takes light time to travel to Earth so we are seeing Gn-z11 so many years in the past.
3. U r right that it is getting father away, but I was looking for that it would be redshifted so much it would be undetectable.
Your turn!

ah that makes sense

1. who named sextans? what is it named after?
2. what discovered the baby boom galaxy? what type of galaxy is it?
3. why are there so many stars forming in the baby boom galaxy? (just a few steps, no explanation needed)

[Locoholic]

ah that makes sense

1. who named sextans? what is it named after?
2. what discovered the baby boom galaxy? what type of galaxy is it?
3. why are there so many stars forming in the baby boom galaxy? (just a few steps, no explanation needed)

1. Johannes Hevelius discovered it, not sure if he named it. It is named after the sextant, an instrument widely used in navigation in the age of exploration.
2. I don't know who discovered it, but I know that it was formally discovered at the Spitzer Science Center. It is a starburst galaxy.
3. Several galaxies are colliding, pulling matter into clumps through gravity, forming protostars.

[IHateClouds]

1. Johannes Hevelius discovered it, not sure if he named it. It is named after the sextant, an instrument widely used in navigation in the age of exploration.
2. I don't know who discovered it, but I know that it was formally discovered at the Spitzer Science Center. It is a starburst galaxy.
3. Several galaxies are colliding, pulling matter into clumps through gravity, forming protostars.

those were exactly what i was going for!

your turn!

[Locoholic]

1. Johannes Hevelius discovered it, not sure if he named it. It is named after the sextant, an instrument widely used in navigation in the age of exploration.
2. I don't know who discovered it, but I know that it was formally discovered at the Spitzer Science Center. It is a starburst galaxy.
3. Several galaxies are colliding, pulling matter into clumps through gravity, forming protostars.

those were exactly what i was going for!

your turn!

Alright! These next questions are a bit random.

1. Rank these stars from brightest to dimmest when viewed in the night sky: Arcturus, Sirius, Vega, Betelgeuse, Antares, Rigel, Procyon, Capella.

2. What is the limit for stars to be considered to be First Magnitude?

3. After which theoretical mass does a star begin to use the CNO cycle more than the proton-proton chain as a method of nucleosynthesis?

[IHateClouds]

1. Rank these stars from brightest to dimmest when viewed in the night sky: Arcturus, Sirius, Vega, Betelgeuse, Antares, Rigel, Procyon, Capella.

2. What is the limit for stars to be considered to be First Magnitude?

3. After which theoretical mass does a star begin to use the CNO cycle more than the proton-proton chain as a method of nucleosynthesis?

1. out of curiousity, how would you go about this other than checking the apparent magnitude of all the stars? like do you keep a list of the stars in order of apparent and aboslute mag on your cheat sheet? altho even that seems slow anyway...



sirius: -1.46
arcturus: -.05
capella: .08
rigel: .13
vega: .026
procyon: .34
betelguese: .5
antares: 1.1




2. less than an apparent magnitude of 1->"first"



3. over 1mass of sun/M