Friday, February 5, 2010

Is it true that the sun rises and sets only in a true ';east to west'; direction on Spring & Autumn equinoxes?

please explain.





and how much of an angle differance is it on Dec. 21 and June 21?





the sun travels in a diagonal path across the sky in its extreme on the winter and summer equinoxes?





is this angle the same differance for all of the northern hemisphere?





please describe and explain.





Thanks for your answers!Is it true that the sun rises and sets only in a true ';east to west'; direction on Spring %26amp; Autumn equinoxes?
Yes, it is true that on the first day of spring and on the first day of autumn - the equinoxes - the Sun rises due east and sets due west.





For an observer in the northern hemisphere, the Sun will rise in the southeast and set in the southwest on the first day of winter - the winter solstice (December 21).





For an observer in the northern hemisphere, the Sun will rise in the northeast and set in the northwest on the first day of summer - the summer solstice (June 21).





The exact angles for sunrise and sunset on the dates of the solstices depends on your latitude within the northern hemisphere, but generally speaking the southeast/southwest and northeast/northwest information stated above is accurate.





If you would like to know the exact azimuth (angle) for sunrise and sunset on the dates of the solstices, please provide me with your latitude.





I hope that you like this answer. If so, please vote for it as the ';Best Answer';. As you may have noticed, most of my answers include a detailed explanation, so that the person who asked the question can learn from it. This takes more time to write, but is certainly worth it from an educational point of view.Is it true that the sun rises and sets only in a true ';east to west'; direction on Spring %26amp; Autumn equinoxes?
I can only answer from observation rather than any astronomical knowledge but it is true that the sun only rises due east on the spring equinox and sets due west on the autumnal equinox. I can't say that I have ever noticed it rise due east and set due west on the same day, though.





On midsummer day, it appears to rise in the north-east (maybe even north-north-east) and sets in the north-west; a transit of about 270 degrees. On midwinter day, it seems to rise in the south-east and set in the south-west (maybe west-south-west), a transit of about 90 degrees.





The angles can't be the same for the whole of the northern hemisphere because the sun doesn't rise or set for six months of the year in the arctic circle because of the angle of the earth's axis relative to it's orbital plane.
Yes





23.5 degrees south of true E-W on Dec. 21, 23.5 degrees north of true E-W on June 21. NOTE: I'm assuming that this is ture





Yes. The sun always follows a diagonal path across the sky in the northern hemisphere. Only at the equator on the equnoxes does the sun rise at true east 90 degrees azimuth and set at true west, 270 degrees azimuth.





Yes. It's the same for the southern hemisphere as well.





It's all because of the tilt of Earth's rotational axis and it's orbit around the Sun

No comments:

Post a Comment