HAT-P36 Transit Data and Times

https://exchangelabsgmu-my.sharepoint.com/:x:/r/personal/xwingfie_masonlive_gmu_edu/_layouts/15/WopiFrame.aspx?sourcedoc=%7B8459A670-25AF-4659-AB32-DE704BABD5B9%7D&file=HATP%2036%20transit%20times%20and%20data.xlsx&action=default


Sorry, I couldn't think of any other way to upload it, but the link should work and the data should be correct. So I will explain exactly what I did just in case the excel is a bit too confusing. I basically found the transit duration of the planet HAT-P36b around its star using the formulas for transit found here:


Most of these values were given by the website:
R*=1.096
Period=1.327347
Semi-Major Axis(a)=0.0238
inclination of Orbit(i)= 0.997564
Solve for b, L
b=a cos(i)-> 0.0238 cos(0.997564)= 0.012908
L is solved using the Pythagorean Theorem: L^2+b^2=R*^2 or L=Sqrt(R*^2-b^2) -> Sqrt(1.096^2- 0.012908^2)=1.09592
2L= Transit Duration= 2.19185

This means that for every 1.327347 Days (or 31.856328 Hours) HAT-P 36b transits in front of its star for 2.19185 hours. The rest was plugged in, calculated and solved for in excel.
So not including the transit that happened today, there will be 20 more viewable transits between today, 3/7/18 and 6/20/18

Comments

Post a Comment

Popular posts from this blog

HW5 Q1 (William Matzko)

Image
1.  For radial velocities, we have the relation k = 28.4 (m/s) p^-(1/3)(M_p*sin(i)) (M_s)^(-2/3), where M_p is the planet mass in Jupiter masses, and M_s is the mass of the star in solar masses. For astrometry, we have  α  = (M_p/M_s)(a)(d)^(-1), where a is the semimajor axis in AU, and d is the distance to the system in parsecs. Just to make things easier to look at, we can make some simplifying assumptions. We are already told to assume sin(i) = 1 in all instances and M_s is the mass of the Sun. We might as well further assume that our target is one Jupiter mass. Further, we know P is proportional to a ^(3/2). The two above equations then reduce to α = 0.001 (a) (d)^-1 k = 28.4 (m/s) (a)^(-1/2) We are given that astrometry is sensitive to  α = 10 micro arcseconds and above, and radial velocities are sensitive to k = 1 m/s and above. Note that only the astrometry method depends on d. We must now find when the astrometry method becomes more sensitive than the rad...
Read more

HW5 Q2, Q3, Q5 (William Matzko)

2. We know the phase amplitude is  ε = A*g*(R/r)^2, where A is the geometric albedo, R is the radius of the planet, r = a(1-e^2)/(1+ecos(f)), and g = 10^(-0.4*m). Here, m is just  m = 0.09( α/100) + 2.39( α/100)^2 - 0.65( α/100), where  α is in degrees (the 100's in the denominator are likewise in degrees). We are working with a Venus analog, so we can assume, in this part, that e = 0, so that r = a. The phase amplitude will be maximum when  α = 0. So, our maximum phase amplitude is then  ε = (0.67) (1)(6050km/108E6km)^2, where I have plugged in the geometric albedo of Venus, the radius of Venus, and Venus' semimajor axis. This yeilds  ε = 2E-9.  Now, we are to assume i = 40 degrees and w = 270 degrees. The effect of w is to orient the orbit such that we have a maximum phase angle at f = 0 . We know the relation between  α and these orbital elements: cos( α) = -sin(i)sin(w+f). Plugging in the numbers and solving for  α yields  α = 50 d...
Read more

HW 5 Q6 (William Matzko)

6. (a)Usually, the temperature on a planet decreases with altitude. However, in inversion layers, this is not the case. In an inversion layer, temperature increases with altitude. Such a thing is important in the atmosphere of exoplanets because it can give insight into what that planet's atmosphere could be composed of. These inversion layers are usually composed of molecules that absorb UV radiation, so finding these inversion layers on exoplanets is desirable if we want to try and find life on them. (b) We know that P = P_0 exp(-z/H), where P is the pressure, P_0 is the pressure at the surface level, z is the altitude above surface level and H is the scale height. We are given that, on Earth z = 8.8 km and H = 8 km. This corresponds to a pressure of ~0.333*P_0. On a modified planet, to find the z at which we have the same pressure, we first must compute the scale height. We can express the scale height equation as H = k*T/(u*m*g), where k is the Boltzmann constant, T is the te...
Read more