The Winter Solstice (mid-winter in the northern hemisphere) occurs on about 21 December when the Sun’s declination is 23. 5 o South (the tropic of Capricorn).
What is the solar declination on December 21st?
Around December 21, the northern hemisphere of the earth is tilted 23.45 degrees away from the sun, which is the winter solstice for the northern hemisphere and the summer solstice for the southern hemisphere.
Where are the sun’s direct rays on December 21?
The sun’s rays are directly overhead along the Tropic of Capricorn (the latitude line at 23.5° south, passing through Brazil, South Africa, and Australia) on December 21. Without the tilt of the earth’s axis, we would have no seasons. The sun’s rays would be directly overhead of the equator all year long.
How do you calculate the declination of the sun?
The following equation can be used to calculate the declination angle: δ=−23.45°×cos(360/365×(d+10)) where the d is the number of days since the start of the year The declination angle equals zero at the equinoxes (March 22 and September 22), positive during the summer in northern hemisphere and negative during winter ...
What is the solar declination angle for January 21st?
The solar declination varies from -23.44° at the (northern hemisphere) winter solstice, through 0° at the vernal equinox, to +23.44° at the summer solstice.
What is the sun’s declination today?
The current Right Ascension of The Sun is 12h 28m 46s and the Declination is -03° 06′ 32” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]).
What is the earth’s declination?
The axis about which the earth rotates is tilted at an angle of 23.45 degrees to the plane of the earth’s orbital plane and the sun’s equator. The earth’s axis results in a day-by-day variation of the angle between the earth–sun line and the earth’s equatorial plane called the solar declination δ.
Which location has the longest day on December 21?
Winter Solstice: In the Southern Hemisphere, today is Summer Solstice — in places like Australia, New Zealand and South Africa , December 21 is the year’s longest day.
Where is the sun located on June 21?
As seen from Earth, the sun is directly overhead at noon 23 1/2 degrees north of the equator , at an imaginary line encircling the globe known as the Tropic of Cancer, named after the constellation Cancer the Crab.
What latitude has the longest day on December 21?
The summer solstice is the longest day of the year and marks the beginning of summer. Winter solstice in the Northern Hemisphere occurs on December 21 or 22, when the sun appears at its most southerly position,directly overhead at the Tropic of Capricorn ( 23 degrees 27 minutes south latitude ).
How do you calculate declination?
Multiply it by -23.44 , the tilt of the Earth’s axis in degrees. The result is the solar declination in degrees for that day of the year. From the example, the cosine of 53.2603 is 0.5982; multiply it by -23.44 to get -14.02 degrees.
Where is the sun at 90 degrees?
For example, at the summer solstice, the Northern Hemisphere faces the sun at maximum tilt, so the sun’s rays strike 23.5 degrees north latitude — the Tropic of Cancer — at a 90 degree angle.
What is the hour angle?
The hour angle is the angular displacement of the sun east or west of the local meridian due to rotation of the earth on its axis at 15° per hour with morning being negative and afternoon being positive. For example, at 10:30 a.m. local apparent time the hour angle is −22.5° (15° per hour times 1.5 hours before noon).
What is the sun’s angle of inclination?
where ψ 1 is the angle of inclination of the spin axis of the Earth with the plane of its orbit, approximately 23.5° . The angle between the sun and the vertical is called the zenith angle. The elevation angle of the sun is 90° minus the zenith angle.
Is angle of declination constant?
Magnetic declination is defined as the angle between magnetic north and true north on the horizontal plane, which is not constant and keeps changing depending upon the position on the earth’s surface and time. The Greek letter δ is used as the symbol for magnetic declination and is also known as magnetic variation.
Why is the sun so bright today 2020?
The reason the Sun looks so bright is because of its distance from Earth . Earth is about 150 million kilometers (93 million miles) from the Sun. ... The Sun is the only star in our solar system. The next closest star is much farther away and in a different solar system.
