RE: Analemma intersection

2018-04-12 Thread Roger W. Sinnott
Roger (and others), A slight correction concerning the motion of Earth's perihelion with respect to the seasons. Owing to precession, the equinoxes and solstices drift slowly westward along the ecliptic in a cycle of about 26,000 years. But at the same time perturbations by the other

Re: Analemma intersection

2018-04-12 Thread Roger Bailey
Hi Dan, To me the value of the EQT at the intersection is an indication of the asymmetry of the analemma caused by the difference between the solstice and perihelion dates. The tilt of the earths axis is one parameter that defines the analemma. This is shown at the extremes, the summer and

Analemma intersection

2018-04-12 Thread Dan-George Uza
Hello, Tomorrow the Sun will have reached the point of intersection in the analemma 8-curve. How do you compute the exact time of intersection (i.e. when both the hour angle and the solar declination match for two days)? And does it have any special significance? Dan