2020, September 14: Venus, Moon Visit Beehive

The crescent moon and Morning Star Venus pass close to the Beehive star cluster.

by Jeffrey L. Hunt

Moving among the dim stars of Cancer, brilliant Morning Star Venus passes the Beehive star cluster during mid-September.

Venus has appeared in the morning sky since mid-June, and it is there into the new year.  It continues to step eastward compared to the starry background in its morning sojourn.

The planet continues to rise over 3.5 hours before sunrise.  By the beginning of morning twilight that starts about 100 minutes before sunrise, Venus sparkles above the skyline in the eastern sky.  Like the other easily visible planets, Venus appears as an overly bright star, the brightest “star” in the sky.  It even outshines Sirius, nighttime’s brightest star.

All the planets appear to move along the ecliptic, an imaginary line that is the plane of the solar system.  The ecliptic makes a great circle around the sky through the familiar zodiacal constellations. Mars, shining in the southern sky during morning twilight, is among the stars of Pisces, while evening planets Jupiter and Saturn are in eastern Sagittarius.

Cancer is a dim constellation between the Gemini Twins and Leo, where Venus moves at month’s end.

The Beehive star cluster is a distant clump of stars that are similar to the famous Pleiades (Seven Sisters), but they are farther away, appearing dimmer to our eyes.  The cluster is also known as the Praesepe (Manger).

The Beehive star cluster looks like a fuzzy cloud to the unaided eye. Its best view is through a binocular, as it spills outside a telescope’s eyepiece.

The cluster is a phase of the life of a star where astronomical theory predicts that stars are formed in bunches.  This cluster has about 200 stars; about a dozen appear through a binocular.

On the morning of September 14, look about 90 minutes before sunrise for brilliant Venus and the lunar crescent that is 12% illuminated.  They are 5.0° apart. The star cluster is 2.7° to the upper left of Venus; that’s about half the Venus – Moon gap.  The lunar crescent is 4.6° to the lower left of the cluster.  The star Delta Cancri (δ Cnc on the chart above) is 0.9° to the upper left of Venus.

Venus is slightly closer to the Beehive on the morning of September 13 and the moon is above the scene.  See the detailed notes below for more specific directions.

Photographers can catch the scene with a camera that has time exposure settings and a tripod mount or another means of holding a steady camera. Exposures from 1 to 5 seconds yield satisfactory results.  Exposures that are longer reveal Earthshine on the moon, sunlight reflected from Earth’s clouds, continents, and oceans that gently illuminate the nighttime moonscape.

The detailed notes that follow provide more specifics:

• September 13: Venus passes 2.3° to the lower right of the Beehive cluster. The planet is also 1.5° to the upper right of (Delta Cancri (δ Cnc). One hour before sunrise, find the brilliant planet about 28° up in the east.  The waning crescent moon (25.3 days past the New Moon phase, 20% illuminated) is over 10° above Venus. The moon is also 6.1° to the lower right of Pollux. 
• September 14: Venus is 5.0° to the right of the crescent moon (26.3d, 12%) and 0.9° to the lower right of δ Cnc. With a binocular observe that the Beehive cluster is 2.7° to the upper left of Venus and 4.6° to the upper right of the lunar crescent. One hour before sunrise, find Venus about 28° up in the east. 

• September 15: One hour before sunrise, Venus is nearly 28° up in the east.  It is 1.4° to the lower right of δ Cnc and 3.3° to the lower right of M44.  All three of these objects are nearly along a line that starts with the star cluster and ends with Venus.  The moon (27.2d, 6%) is about 15° up in the east.  It is 5.4° to the upper left of Regulus

Here is a daily summary about the planets during September.