Astrophysics (2 Viewers)

[MuffinMan]

General discussion on astrophysics

 

[bEAbEA]

hard as!!!!!

 

[SmileyCam]

It wasn't that bad, like the rest of the exam it was very biased towards equations and calculations, so I loked it ^_^, and the 7 marker wasn't too bad either

 

[baby_pea]

parallax!
the star shift

 

[charred remains]

Generally better than the rest of the fucked paper... The paper needed mixing viagra with rogain, although I'm not sure how that would end up... There wasn't too much I had no idea about in astro.

 

[Bronny_Mac]

Astro was stupid, not enough calculations, and what was with the rest of the paper "evaluate this" "justify that" .
WOO NO MORE TESTS!!!!

 

[tim_dawborn]

i thort the astro was pretty easy except for that parallax piece a shit - nfi what to do with it lol

oh well at least it is all over now

 

[Rekkusu]

XD lol I was like partly screwed because I forgot the actual length of a parsec...justification was abit weird.

Though I have to say Q30: C was abit weird, I mean so many technological advances could have happened..

 

[SmileyCam]

i thort the astro was pretty easy except for that parallax piece a shit - nfi what to do with it lol

oh well at least it is all over now

I just worked out the distance between them and used the d=1/p, done yay

 

[baby_pea]

That's what I did, but doesn't seem right. I'm not the type to assume I'm correct either.

 

[r.haidar]

i got 5 pages down for the 7 marker... overkill? lol the parallax was just d = 1/p or some shit... i got 1.31 or some shit

good exam

peace out
ralph

 

[charred remains]

Answer for parralax (I think)...

Find out how many squares the thing moved, 7. something I think, theres 10 squares in 1", so 10/7.something = p....and d =1/p gives it. A tad annoying but if i've gone awfully wrong I apologise.

 

[kdes17]

i found it to be pretty good. got the parallax thing wrong, but thats only 2 marks, so not too worried. my school did qunta to quarks, i picked astro cos quanta's a piece of shit. i learnt astro from scratch yesterday. quite happy with my decision to change option topics.

 

[tabularasa]

I thought astor was alright the big mark u could writes heaps on so i thought thta wasc cool. conneting eveyrthing was difficult but there wasload i think i wrote about 5 pages,.

Parralax i used pythagorus theorum to get it. weird way but the answer seemed oik.

 

[kdes17]

Parralax i used pythagorus theorum to get it. weird way but the answer seemed oik.

ME too! i just assumed that was wrong cos every else is using d = 1/p. what was your final answer btw?

 

[flying_dragon]

I used Ia/Ib = 100^((mb-ma)/5) on the compare question between Alpha Centauri and Proxima Centauri, and got that the brighter one is something like 10000 times brighter than the other...To me, this seems a bit large...please confirm or deny the accuracy of this number...

 

[leumas_au]

I used Ia/Ib = 100^((mb-ma)/5) on the compare question between Alpha Centauri and Proxima Centauri, and got that the brighter one is something like 10000 times brighter than the other...To me, this seems a bit large...please confirm or deny the accuracy of this number...

I think the difference was less than that, or at least thats what I got. maybe Centauri was 6 times brighter, i am still in a bit of a dase hey im sure they will be lenient, the questions were kinda hard. 10,000 is a large number!

Im pretty sure you had to work out the apparent magnitude from the absolute magnitude given, which is why the question was worth 4mks instead of the usual three.
that question took me ages.
I think the equation to use was M = m-5log(d/10) and work backwards to get the apparent magnitude(m) value.
This would also be why they gave you the value of d to be 1.3pc.
Then you use Ia/Ib = 100^((mb-ma)/5) with the m magnitude determined from the other formula to get the ratio of the apparent brightnesses.
Im probably wrong, but this is how I answered it.
I dont remember any of the values I obtained, but I am glad that it is over.

 

[tabularasa]

for P i got 0.77 and distance i got liiek was 1.7 somehtign or other. calculations always screw me up.

 

[slutmonkey23]

i think cephied variables should anally rape itself. i hate them. with such a passion as you can tell.

and that bloody "find out the distance from this parsec graph" GAH!

otehr than that, DAMNED shite paper
WOOT WOOT!! bring on the sleeping.

 

[powerhouse]

Finding the mass of the smaller star in a binary system you'd use the m1 + m2 thing, however, it says one star is 4 times the other so I assumed 5M = answer and divided the answer of m1 + m2 by 5.

With the trigonometric parallax thing I used pythagorus' theorem and found d to be .71 arcsecs. So I used d = 1 / .71 = 1.4 parsecs.

And yes, for the question on the brightness of each star I found that Alpha Centuri A was >10,000 times brighter than Proxima Centuri. I remember having a 6 somewhere in my answer.