2021: June 15-17: Moon Passes Leo

June 15 – June 17, 2021:  The evening waxing moon passes Leo the Lion.  On June 15, the moon is near Regulus and Eta Leonis.  The next evening, June 16, the lunar orb is between Regulus and Denebola.  On June 17, the moon is beneath Denebola.

2021, June 15 – June 17: The moon passes Leo in the western evening sky.
Chart Caption – 2021, June 15 – June 17: The moon passes Leo in the western evening sky.

by Jeffrey L. Hunt

During the next three evenings, the evening waxing moon is near Leo.  The westward facing Lion is tilting toward the western horizon. The constellation is represented by a backwards question mark that is the head of the celestial big cat.  This figure is sometimes known as the “Sickle of Leo,” the namesake of a farmer’s tool.

The haunches are made by a triangle that includes the tail, Denebola, the constellation’s second brightest star.

The brightest star in the constellation is Regulus.  The star’s name means “the prince.” Its distinctly bluish tint indicates that it is hotter than the sun.  At a distance of about 80 light years, the star is about 275 times brighter than our sun.

Regulus is the star that is closest to the ecliptic, the plane of the solar system.  The sun, moon, and planets pass nearby. Next month, Venus and Mars pass the star.  Regulus is behind the sun on August 22, reappearing in the eastern sky during early September.  On the morning of September 5, the old moon appears 7.3° to the star’s upper left before sunrise.

During the next few evenings, step outside one hour after sunset, the waxing moon is in the western sky.  Here’s what to look for:

2021, June 15: Through a binocular notice Eta Leonis (η Leo) near the lunar crescent.
Chart Caption – 2021, June 15: Through a binocular notice Eta Leonis (η Leo) near the lunar crescent.

June 15: The moon, 28% illuminated, is over 30° up in the west-southwest.  The crescent is 1.1° to the upper left of Eta Leonis (η Leo on the chart).  From the Caribbean, Central America, and northern South America, the moon blocks the star.  For more information about the lunar occultation see this link.  From the Americas, use a binocular to see the star with the lunar crescent.

June 16:One hour after sunset, the moon, 39% illuminated, is nearly 40° up in the west-southwest.  Below the Lion, the thick crescent is 13.0° to the upper left of Regulus, 12.0° to the lower right of Denebola, and 5.2° to the lower left of Chertan.

June 17: The moon is in Virgo this evening.  One hour after sunset, the nearly half-full moon is nearly 40° above the southwestern horizon. The lunar orb is 3.9° to the upper right of Zavijava, the second brightest star in Virgo, and 8.9° to the lower left of Denebola.  The name Zavijava means “the corner of the barking dog.”

Look for the moon each clear evening as it passes Leo and its phase waxes.

Articles and Summaries



Categories: Astronomy, Sky Watching

Tags: , , , ,

Leave a Reply

%d bloggers like this: