Celestial forecast| before the arrival of the winter solstice Don't miss the "super little moon" in the night sky

December 19 "Super Little Moon"

December 21, 23:59 Winter solstice

The full moon on December 19, Beijing time, is just the opposite of the "super moon" "super moon", because around the day of the full moon, just the moon over the apogee, this full moon will look a little smaller than usual. If you shoot a "supermoon" and a "superminulator" at the same location with the same equipment and parameters, you can merge the two photos together later and compare the size of the moon at perigee and apogee. However, the size of the moon is also affected by the shape of the earth, and people in different regions will see the size of the moon slightly different.

December 21, 23:59 Beijing time is the winter solstice, which is also an important solar term in the 24 solar terms of the lunar calendar. In northern China, there is a custom of eating dumplings every year on the winter solstice.

The winter solstice is the 22nd solar term of the "twenty-four solar terms", with a solar ecliptic longitude of 270°, which generally occurs between December 21 and 23 of the Gregorian calendar every year. On the day of the winter solstice, the sun shines directly on the Tropic of Cancer, and the northern hemisphere has the smallest solar altitude angle, which is the shortest day and the longest night in all parts of the northern hemisphere. After the winter solstice, the direct solar point begins to move north from the Tropic of Cancer (23 ° 26 ′S), and the days in the northern hemisphere (china is located in the northern hemisphere) will increase day by day.

Happy Winter Solstice!

Introduction to the Presenter

Huijuan Wang, Ph.D., is a researcher of the Nebula Program of the National Astronomical Observatories of the Chinese Academy of Sciences and a master tutor of the University of Chinese Academy of Sciences. He is mainly engaged in the research of stellar physics, high-precision photometry and spectral detection methods.

Rotating Editor-in-Chief: Ran Li

Column planning: Wan Haoyi

Co-ordinator Producer: Yuan Fengfang

Video script: Wang Huijuan, Yuan Fengfang

Choreographer: Song Yajuan, Cai Lin

Camera: Xiao Chunfang

Post-editing: Bowen Zhang

Editors: Zhao Yuhao, Qiqi

China Association for Science and Technology National Astronomical Observatory Guangming Net

Co-produced

Video and image credits:

Sky Guide

Solar Walk

duke

EllieYuan

Wiki

https://svs.gsfc.nasa.gov

https://www.timeanddate.com

National Astronomical Journal of China, November 2021

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