2018, December 13: Morning Star Venus Reaches Earliest Rise Time


Venus’ rapid appearance in the morning occurred quickly after its inferior conjunction in late October.  On December 13, it has its earliest rise time (3:23 a.m. CST in Chicago). This earliest rise time is 48 days after its conjunction with the sun. On this morning, the Venus-Spica separation is13.8°.

Nearly a week later (December 19), the time interval between Venus rise and sunrise is greatest, 3 hours, 51 minutes, during this morning appearance. While the Venus rising time is still 3:23 a.m. CST (in Chicago), sunrise changes 4 minutes earlier in a week week. The gap between sunrise and Venus rising now decreases, on average, about 1 minute each morning until Venus rises at the beginning of twilight less than three months from this morning. Venus and Spica are 10.6° apart. This morning Venus is 4.3° above Zubenelgenubi (α Lib, m = 2.8). Through a telescope, Venus has a very thick morning crescent phase that is 40% illuminated. As it approaches its greatest elongation, watch the phase grow to the morning half phase during the next 18 mornings.

Our feature article about the morning appearance of Venus:

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