## Astronomy C

hippo9
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### Re: Astronomy C

syo_astro wrote:
October 18th, 2019, 5:51 pm
hippo9 wrote:
October 18th, 2019, 5:29 pm
So for calculating recessional velocity from redshift I've found 2 different equations:

The far simpler z=v/c
As well as the more complicated (v/c)= ((z+1)^2-1)/((z+1^2+1)

Which one is correct then? Or are they for different situations that I'm oblivious to?
Yup, they're used in different situations! The simpler form is used at "low" velocities (specifically: non-relativistic), while the other form is more general (called "relativistic Doppler shift"). hippo9 also asked on chat why on some people use "z=v/c" vs. "z=~v/c" (implying the equality exact or approximate). I think if people use "=", they are saying it's an approximation but "basically the same", so it's fair to say that "=". Need a more detailed proof, or does that suffice? Practically speaking, you just have to be on lookout for whether something is explicitly or implicitly stated to be at relativistic speeds.
Ok cool thanks, just look out for the diction I guess.
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Blank25
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### Re: Astronomy C

What's the best way to split up studying between partners? Or should me and my partner not split up the work?
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Name
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### Re: Astronomy C

Blank25 wrote:
October 27th, 2019, 6:49 pm
What's the best way to split up studying between partners? Or should me and my partner not split up the work?
Because it's almost impossible to solo an astro test prob split it. I've personally found it best to split math stuff and DSO stuff. You should still have a good understanding of the other section though.
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PM2017
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### Re: Astronomy C

Name wrote:
October 28th, 2019, 1:01 pm
Blank25 wrote:
October 27th, 2019, 6:49 pm
What's the best way to split up studying between partners? Or should me and my partner not split up the work?
Because it's almost impossible to solo an astro test prob split it. I've personally found it best to split math stuff and DSO stuff. You should still have a good understanding of the other section though.
I'd say the above is definitely true for during the test itself (worked well for us, anyways).

Just be wary that sometimes tests are disproportionately weighted towards one side or another, so like Name said, make sure to be well-versed in the other topic as well. When my partner and I studied and made notes we both worked on both sections.
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### Re: Astronomy C

Hi everyone! I've put up my astro exam for UT invite here. Hope this is helpful! Let me know by email if you have any questions.

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### Re: Astronomy C

Just wanted to let y'all know that the webinars for this year went up a couple of weeks ago! You can find them here.
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kalimarieyork
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### Re: Astronomy C

So what's the focus for 2019-2020 season?

pb5754
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### Re: Astronomy C

kalimarieyork wrote:
November 18th, 2019, 10:08 am
So what's the focus for 2019-2020 season?
stellar/galactic formation/evolution
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Waterpigcow
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### Re: Astronomy C

Is it a worthwhile investment to write programs on my ti-84/laptop to quickly solve math sections? my astronomy team does decent at dso questions and stellar evolution/conceptual stuff but we struggle with the math every year. I figure using the formula sheet on the wiki i could write a bunch of programs to solve for that stuff. would it be better if we actually learned the math or would a couple programs be enough? I'm pretty sure i could write the programs in less time to learn the math as well and since everyone on the team is busy i feel like it'd be a more efficient use of time.

Unome
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### Re: Astronomy C

Waterpigcow wrote:
November 18th, 2019, 6:03 pm
Is it a worthwhile investment to write programs on my ti-84/laptop to quickly solve math sections? my astronomy team does decent at dso questions and stellar evolution/conceptual stuff but we struggle with the math every year. I figure using the formula sheet on the wiki i could write a bunch of programs to solve for that stuff. would it be better if we actually learned the math or would a couple programs be enough? I'm pretty sure i could write the programs in less time to learn the math as well and since everyone on the team is busy i feel like it'd be a more efficient use of time.
It's more important to know how they work. After that, I would say go ahead and write a program.
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