clarify why parallax just works for stars that r less than 200 light years away.
It is because of the smaller angles involved in the greater distances, which cause to many observation errors for calculations to be valid.
Please correct me if I'm wrong, thanks
You are 100% correct...I think...
you are correct. The errors are inherent in any observation, but at small angles, those tiny errors in the calculations are the major factor.
Picture your mom 10 feet away, then 10,000 feet away. Think you could see if her eyes were looking at you at that distance? No, the error in your resolution would be greater then the size of her eye ball.
thanks bobpursely, I really like your example:-)
You are correct, parallax works best for stars that are closer to us, specifically within 200 light years. The reason for this is that parallax relies on measuring the apparent shift in a star's position as seen from two different locations on Earth's orbit around the Sun.
When a star is closer to us, the shift in its position is larger because the angle between the two observing positions is larger. This makes it easier to measure and calculate the parallax angle accurately. However, as the distance to the star increases, the angle becomes smaller, making it harder to measure with precision.
Observational errors like atmospheric turbulence, instrumental limitations, and measurement uncertainties become more significant for smaller angles. These errors can introduce inaccuracies in the calculated parallax angle, leading to less reliable distance measurements for stars located farther away.
To summarize, parallax just works for stars that are less than 200 light years away because the larger parallax angles associated with closer stars allow for more accurate measurements, while the smaller angles for more distant stars result in increased observational errors and reduced reliability of distance calculations.