What is the relationship between orbital semi latus rectum and angular momentum?

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
3 replies · 5K views
Penguinluons
Messages
5
Reaction score
0
Hi. I have recently been trying my hands at calculating a few orbits but have encountered difficulties in trying to 'understand' the semi latus rectum.

P=h^2/GM

What does it have to do with the orbiting object's angular momentum? How come I get different values when I derive it from other equations? Please help me as I need to understand this to move on to elliptic orbits.

(Note: When I derived P from other equations, I got different values but they were all quite close to each other.)
 
Astronomy news on Phys.org
Which numbers and formulas do you use to calculate the values and what are the results?
Penguinluons said:
(Note: When I derived P from other equations, I got different values but they were all quite close to each other.)
Could that come from rounding errors or measurement uncertainties?
Penguinluons said:
What does it have to do with the orbiting object's angular momentum?
Both describe some aspect of the orbital motion, what is surprising about equations involving both?
 
mfb said:
Which numbers and formulas do you use to calculate the values and what are the results?
Could that come from rounding errors or measurement uncertainties?
Both describe some aspect of the orbital motion, what is surprising about equations involving both?

I used the equations for apoapsis and periapsis as well as the general equation r=P/1+e cosθ. I tried deriving p from the semi major axis as well.e had an accuracy of about 10 digits. It was an elliptic orbit. Does this therefore place limitations on the mass of my orbiting object?