On December 19 at 8:43PM EST, slightly over 1.5 days before the winter solstice on the 21st, the New Moon is in Ophiuchus. The New Moon marks the start of Lunation 1274 which ends 29.76 days later with the January New Moon in Sagittarius on the 18th at 2:52PM EST.
The Full Moon on the December 4 is called the Moon before Yule, Long Night Moon, or Cold Moon. It occurs at 6:14PM EST in Taurus and is the 3rd supermoon in a row, 2nd largest of the year behind that of November! Full Moon occurs 12 hours and 7 minutes after perigee (minimum monthly lunar distance) and this proximity causes it to appear larger and brighter than normal.
Although the New Moon on the 19th can't be seen, it would be a "submoon" (smaller than normal) if it were visible because it is farther when near apogee (see below). If at a syzygy, where the Moon's tilted orbit intersects with Earth's, a submoon like this would produce an annular solar eclipse!
