Using Polaris and the Big Dipper to approximate local standard time


In this paper we introduce methods for approximating local standard time in the Northern Hemisphere using Polaris and the Big Dipper as well as alternative reference stars, and describe in detail how to construct a device we call a dipperclock to facilitate this process. An alternative method which does not require a dipperclock is also discussed. Ways of constructing dipperclocks which glow in the dark are presented. The accuracy of dipperclocks is examined, both theoretically and through field testing. A java program is provided for creating dipperclocks customized to a particular year-long time period and place to get improved accuracy. Basic astronomical definitions and justifications of the results are provided. We also discuss the use of dipperclocks to find longitude and latitude.

Share and Cite:

Kaufman Jr, E. , Page, C. and Watson, C. (2012) Using Polaris and the Big Dipper to approximate local standard time. Natural Science, 4, 1042-1055. doi: 10.4236/ns.2012.412133.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Collins, E.B. (1926) Useful stargazing. Scientific Ameri- can, 134, 58-61.
[2] Kaufman Jr., E.H. (2011) How to find celestial objects by starhopping.
[3] Mammana, D. (1990) How to tell time by the big dipper.
[4] Miles, K.A. and Peters, C.F. II (1997) What the big dip- per can tell you.
[5] Pasachoff, J.M. (2000) A field guide to the stars and planets. 4th Edition, Houghton Mifflin, New York.
[6] Layton, B. and Huffman, A. (1999) Telling time by the big dipper.
[7] Wylie, C.C. and Merrymon, W.W. (1926) Time by the big dipper. Popular Astronomy, 34, 229.
[8] The Editors of Sky and Telescope (2011) Make a star wheel! Sky and Telescope.
[9] Chai, Q.H., Henry C.S.S., Tan C.Y. and Wong S.L. GEK 1506, heavenly mathematics: Cultural astronomy, group 32 methods of telling time. National University of Sin- gapore, Singapore.
[10] Jen, Dr. and Van Dresar, J. (2008) Nocturnal time dial part II: Getting the time using the big dipper. 4Physics.
[11] Schatz, D. and Allen, P. (2011) Make a star clock! Sky and Telescope.
[12] Uses of the astrolabe.
[13] Kaufman, E.H. Jr., Page, C.R. and Watson, C.R. (2012) Dipperclock.
[14] Latitude and longitude of a point. Google Maps.
[15] US Naval Observatory (2000) Earth’s seasons: Equinoxes, perihelion, solstices, and aphelion, 2000-2020.
[16] Favill, J. (1940) Primer of celestial navigation. Cornell Maritime Press, New York.
[17] Nassau, J. (1948) Practical astronomy. McGraw Hill, New York.
[18] Kaufman Jr., E.H. (2011) A java program for drawing dipperclocks.
[19] Java download for a PC. (2009)
[20] Eck, D.J. (2010) Introduction to programming using java. 5th Edition.
[21] Glow in the dark photo paper. (2011)
[22] Glow in the dark paint. (2011)
[23] Timekeeping. (2010)

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.