1) I see. Is there a way to express the scenario when the planet is in front of the star in terms of F* and Fp?
2) Agreed.
3) Well, I think you have a straight line when both are radiating, and then a large dip means the planet is now not radiating as it is in front of the star AND the star's...
1) Okay, so my logic there was that when the planet is blocking the star, the flux is F* - the area of the planet, and I thought that that would be F* - the planet's flux, but now that you've pointed it out, that doesn't make much sense. So is it just F* - area of the planet?
2) Actually now...
Yes, I meant radius :) Thank you so much for walking me through it! If I may ask you for a brief advice on the next part of the question:
Three different flux levels can be measured (assuming the star’s luminosity does not vary): (1) when neither the star nor the planet block one another; (2)...
Ah, I see. So the relationship is radius^2 ∝ area (or is it radius ∝ area^2? I get confused). So it's x^2 = 3/10,000. x = 0.0173 the area of the Sun, which is 0.0173*5*10^5 km = 8650 km (or slightly bigger than Earth).
Is this correct?
Ah, I'm starting to understand. No, it's an astronomy class, definitely not a signal processing/engineering or anything like that. However, I do need to use all of the information given.
Okay, so how do I get the smallest planet detectable from a 3/10,000 flux blockage minimum. I need to know...
Well an area of a circle is pi*r^2, therefore the area blocked would decrease with the square of the radius. So if the planet has 1/2 the radius of the star, then it would block 1/4th of the starlight?
I just don't know how to convert the S/N ratio with the 3 standard deviation sensitivity into...
Well, my guess is this - I know how big the star is and the SNR tells me the resolution of the instrument, which is to say how small an object it can distinguish from the background noise - in this case a dip in the flux of 3 standard deviations of the noise. So I need to use this information to...
Please help me with this astronomy problem. I am supposed to calculate the smallest planet that is detectable with the transit method, given a signal to noise ratio and a star's radius:
Suppose the star is seen at its distance D with a signal to noise ratio of S/N = 10^4. This means that in...
I am having trouble with this number density astrophysics question. Any help is greatly appreciated:
Consider a galactic disk with radius much larger than its thickness. Let R be the radius and the thickness be 2H where H is the ‘scale height’ of the disk. For a population of objects with...
Hm, well I'm not sure how to interpret yours.
When I look at mine:
https://www.wolframalpha.com/input/?i=220000%3Dsqrt%281.4*10%5E32*%28ln%28%286.17*10%5E20%2Bx%29%2F%286.17*10%5E20%29%29-+%28x%2F%286.17*10%5E20%2Bx%29%29*%281%2Fx%29%29
I see that the curve for x ends right at...
@SammyS - Thank you so much, that worked. I got a graph, but I'm not sure how to interpret it...
Here's the equation in a form that works for WolframAlpha
220000=sqrt(1.4*10^32*(ln((6.17*10^20+x)/(6.17*10^20))- (x/(6.17*10^20+x))*(1/x))
Yeah, I guess it's a function because the radius is a...
Basically, the way I derived it (and this may now be more appropriate for the astrophysics section)
is by using the equation
V=\sqrt{\frac{GM}{R}}
I want to estimate the point at which orbital velocity and mass are no longer linearly related. The velocity of the flat portion of the...