Determination of the Declination of the Sun on a Given Day
Abstract
In this article we discuss a novel and low cost experiment to determine the angle of declination of the sun on a chosen day. The declination of the sun varies from + 23.5 degrees to - 23.5 degrees in the course of one year. If the zenith angle of the sun is measured as a function of its hour angle on a particular day, it is possible to calculate the angle of declination by using of spherical trigonometric relationship between them. The zenith angle is determined by using the shadow length of a vertically placed rod. The hour angle is determined from the position of shadow as a function of time. The value of solar declination may be compared with that available in almanacs.
References
Prajavani. (dated 26th July (2011). Local Kannada newspaper daily, Karnataka, India.
Rai, G.D. (2009), Solar energy Utilization, 5th Edition, Ninth Reprint, Khanna Publishers, Darya Ganj, New Delhi, India.
Roth, G.D. (1975). Astronomy: A Handbook. Sky Publishing Corporation, Cambridge: Massachusetts.
Texas A & M University (TAMU) (2011). http://faculty.physics.tamu.edu/krisciunas/ra_dec_sun.html
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