## Astronomy

EastStroudsburg13
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### Re: Astronomy

I got 3rd at regionals, and it was pretty much me that did a lot of the work. The biggest problem I had was trying to relate apparent and absolute magnitude to things like distance and luminosity. How would you figure that out?

My next problem was the Julian Calendar. How do the dates work for that?
Last edited by EastStroudsburg13 on March 17th, 2009, 12:46 pm, edited 1 time in total.
East Stroudsburg South Class of 2012, Alumnus of JT Lambert, Drexel University Class of 2017

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celtics09
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### Re: Astronomy

There is an excellent source out there,

Click on this website it will give you all the mathematical relations that you need to know
http://scioly.org/w/images/c/c6/Formula_Sheet.pdf

The julian date
http://aa.usno.navy.mil/data/docs/JulianDate.php
Washington DC Nationals - 2008
Astronomy 27th
Fermi Questions 21st
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Augusta Nationals-2009
Astronomy 18th
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EastStroudsburg13
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### Re: Astronomy

Click on this website it will give you all the mathematical relations that you need to know
http://scioly.org/w/images/c/c6/Formula_Sheet.pdf
I actually printed that out and put it in my binder. I couldn't find the specific fourmula for apparent/absolute magnitude.

The Julian Date makes sense now, thanks!
East Stroudsburg South Class of 2012, Alumnus of JT Lambert, Drexel University Class of 2017

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Glacierguy1
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### Re: Astronomy

What did they give you in the "apparent/absolute magnitude problem"
SAVE OUR GLACIERS.

sweetcoop
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### Re: Astronomy

Wow my team needs a lot of help on this event cause we took 19th out of 38 teams

The 10 most important two letter words.
If it is to be, it is up to me

jtolley
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### Re: Astronomy

[quote="EASTstroudsburg13"]
I couldn't find the specific fourmula for apparent/absolute magnitude.[quote]

Are you stating that you don't want merely ratio formulas which compare such things like two star's luminosity's to their distances...?

Well, there are several different formulas that you can use to find apparent magnitude and absolute magnitude without having to rely on information about another star.

Of course, there is the one we should ALL know:

m - M = 5log(d/10), where d is in parsecs. So if you know distance and a type of magnitude, you can find the other magnitude.

Now, SPECIFIC formulas for magnitude are a little weirder. First, there is this one relating absolute magnitude to period (in days):

M = -2.81log(P) - 1.43 (just for Cepheids). This comes from the period-luminosity relationship and some guy saying that this the relationship between them.

There is also this formula relating luminosity and abs magnitude:

L = 3.362 x 10^((140-2M)/5).

Are these the sort of things you are looking for??
Out of 32 teams at state:

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EastStroudsburg13
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### Re: Astronomy

OK, that sounds like it would have helped. I don't remember the exact questions though, and our region doesn't make the tests public (I don't think).
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meg312
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### Help!

Hi guys,
It's obvious y'all know what you're talking about. I, however, do not know a thing about astronomy except for how to find the Big Dipper and Orion. Somehow, I was signed up for Astronomy. Now, with two weeks before the competition, I am realizing I need some major help! Any tips?

herewegoagain365
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### Re: Astronomy

It's probably a good idea to check out the scioly.org Astronomy wiki (look under "Board Index"). It's also a good idea to look up and take notes on each of the topics on the rules sheet (since you're allowed to take either a binder or laptop, put your notes on there). Good luck!

herewegoagain365
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### Re: Astronomy

Here's the link for the wiki:
http://scioly.org/wiki/Astronomy