Even though the longest day occurs on the June solstice everywhere in the Northern Hemisphere, this is NOT the day of earliest sunrise and latest sunset. Similarly, the shortest day at the December solstice in not the day of latest sunrise and earliest sunset. An analysis combines the vertical change of the position of the Sun due to the tilt of Earth’s axis with the horizontal change which depends on the two factors of an elliptical orbit and the axial tilt. The result is an analemma which shows the position of the noon Sun in the sky. This position is changed into a time at the meridian before or after noon, and this is referred to as the equation of time. Next, a way of determining the time between a rising Sun and its passage across the meridian (equivalent to the meridian to the setting Sun) is shown for a particular latitude. This is then applied to calculate how many days before or after the solstices does the earliest and latest sunrise as well as the latest and earliest sunset occur. These figures are derived for 60 cities in the USA. The selection was initially based on the most populous urban areas but was extended to ensure that each of the 50 states has a representative city.
| Published in | American Journal of Astronomy and Astrophysics (Volume 9, Issue 1) |
| DOI | 10.11648/j.ajaa.20210901.11 |
| Page(s) | 1-7 |
| Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
| Copyright |
Copyright © The Author(s), 2024. Published by Science Publishing Group |
Solstice, Elevation, Obliquity, Elliptical Orbit, Meridian, Analemma, Equation of Time
| [1] | astropixels.com/ephemeris/astrocal/astrocal2020cst.html. |
| [2] | P. Kenneth Seidelmann (ed), Explanatory Supplement to the Astronomical Almanac, University Science Books, Sausalito California, 2006. |
| [3] | Teo Shin Yeow, The Analemma for Latitudinally-Challenged People, http://www.math.nus.edu.sg/aslaksen/projects/tsy.pdf, Singapore, 2002. |
| [4] | D. Fletcher, Solar Declination, http://holodeck.st.usm.edu/vrcomputing/vic_t/tutorials/solar/declination.shtml, 2002. |
| [5] | Peter Duffett-Smith, Practical Astronomy with your Calculator, 3rd edition, Cambridge University Press, 1992. |
| [6] | James B. Kaler, The Ever-Changing Sky – A Guide to the Celestial Sphere, Cambridge University Press, Cambridge, 2002. |
| [7] | H. R. Mills, Positional Astronomy and Astro-Navigation Made Easy, Stanley Thornes Ltd., 1978. |
| [8] | Ian Ridpath (ed), Norton’s 2000.0 Star Atlas and Reference Handbook, 18th edition, Longman Group UK Ltd. Essex. |
| [9] | Stan Wagon, “Why December 21 is the Longest Day of the Year”, Mathematics Magazine, 63, 1990, 307-311. |
APA Style
Keith John Treschman. (2021). Calculation of Solar Motion for Localities in the USA. American Journal of Astronomy and Astrophysics, 9(1), 1-7. https://doi.org/10.11648/j.ajaa.20210901.11
ACS Style
Keith John Treschman. Calculation of Solar Motion for Localities in the USA. Am. J. Astron. Astrophys. 2021, 9(1), 1-7. doi: 10.11648/j.ajaa.20210901.11
AMA Style
Keith John Treschman. Calculation of Solar Motion for Localities in the USA. Am J Astron Astrophys. 2021;9(1):1-7. doi: 10.11648/j.ajaa.20210901.11
Share This Article
Twitter
Linked In
Facebook
Copy
Download@article{10.11648/j.ajaa.20210901.11,
author = {Keith John Treschman},
title = {Calculation of Solar Motion for Localities in the USA},
journal = {American Journal of Astronomy and Astrophysics},
volume = {9},
number = {1},
pages = {1-7},
doi = {10.11648/j.ajaa.20210901.11},
url = {https://doi.org/10.11648/j.ajaa.20210901.11},
eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajaa.20210901.11},
abstract = {Even though the longest day occurs on the June solstice everywhere in the Northern Hemisphere, this is NOT the day of earliest sunrise and latest sunset. Similarly, the shortest day at the December solstice in not the day of latest sunrise and earliest sunset. An analysis combines the vertical change of the position of the Sun due to the tilt of Earth’s axis with the horizontal change which depends on the two factors of an elliptical orbit and the axial tilt. The result is an analemma which shows the position of the noon Sun in the sky. This position is changed into a time at the meridian before or after noon, and this is referred to as the equation of time. Next, a way of determining the time between a rising Sun and its passage across the meridian (equivalent to the meridian to the setting Sun) is shown for a particular latitude. This is then applied to calculate how many days before or after the solstices does the earliest and latest sunrise as well as the latest and earliest sunset occur. These figures are derived for 60 cities in the USA. The selection was initially based on the most populous urban areas but was extended to ensure that each of the 50 states has a representative city.},
year = {2021}
}
TY - JOUR T1 - Calculation of Solar Motion for Localities in the USA AU - Keith John Treschman Y1 - 2021/01/12 PY - 2021 N1 - https://doi.org/10.11648/j.ajaa.20210901.11 DO - 10.11648/j.ajaa.20210901.11 T2 - American Journal of Astronomy and Astrophysics JF - American Journal of Astronomy and Astrophysics JO - American Journal of Astronomy and Astrophysics SP - 1 EP - 7 PB - Science Publishing Group SN - 2376-4686 UR - https://doi.org/10.11648/j.ajaa.20210901.11 AB - Even though the longest day occurs on the June solstice everywhere in the Northern Hemisphere, this is NOT the day of earliest sunrise and latest sunset. Similarly, the shortest day at the December solstice in not the day of latest sunrise and earliest sunset. An analysis combines the vertical change of the position of the Sun due to the tilt of Earth’s axis with the horizontal change which depends on the two factors of an elliptical orbit and the axial tilt. The result is an analemma which shows the position of the noon Sun in the sky. This position is changed into a time at the meridian before or after noon, and this is referred to as the equation of time. Next, a way of determining the time between a rising Sun and its passage across the meridian (equivalent to the meridian to the setting Sun) is shown for a particular latitude. This is then applied to calculate how many days before or after the solstices does the earliest and latest sunrise as well as the latest and earliest sunset occur. These figures are derived for 60 cities in the USA. The selection was initially based on the most populous urban areas but was extended to ensure that each of the 50 states has a representative city. VL - 9 IS - 1 ER -
Information
Email: