by Bob Hayward –
Astronomers at the Pisgah Astronomical Research Institute point out that at 11:48 p.m. EST on Monday, December 21, 2015 the Sun will be at its most southern point in the sky for the year. This is the winter solstice and marks the first moment of winter.
What is the astronomical significance of this event? At this moment the Sun in its apparent path around the sky will stand directly over the Tropic of Capricorn. For an observer at that latitude, the Sun will appear directly overhead at noon. However, from Western North Carolina, the noontime Sun will appear only about 31 degrees above the southern horizon, its lowest point of the year. What’s more, the Sun rises at its most southern point along the southeastern horizon and sets at its most southern point on the southwestern horizon.
Around this date the days are the shortest of the year and the length of the night the longest. For example, in Brevard sunrise occurs at 7:36 a.m. EST and sunset at 5:22 p.m. Thus, it is above the horizon only 9 hours 46 minutes. And viewers in Asheville, which is slightly north of Brevard, will see the Sun for 2 minutes less that day.
After the winter solstice, the Sun begins its return to the north. The days will gradually lengthen and the Sun will appear higher in the sky at noon. It will rise farther to the north along the southeastern horizon each morning and also set farther to the north.
This continues through the spring or vernal equinox at 12:30.m. EDT on March 20 until the summer solstice at 6:34 p.m. EDT June 20. At that point the Sun reaches its most northern point in the sky directly over the Tropic of Cancer and the noontime Sun in our area will be seen at 78 degrees above the southern horizon.
About PARI
PARI is a public not-for-profit public foundation established in 1998. Located in the Pisgah National Forest southwest of Asheville, NC, PARI offers STEM educational programs at all levels, from K-12 through post-graduate research. For more information about PARI and its programs, visit www.pari.edu.