Skywatch Line for Monday and Tuesday June 19th, and 20th, 2023

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday June 19th, and 20th, written by Joe Slomka.

The Sun sets at 8:37 PM; night falls at 10:54. Dawn begins at 3:00 AM and ends with the Sun rising at 5:17.

Monday’s Moon rises, in western Gemini, at 6:04 AM. One day past “NEW”, 10° high at 9:15 PM, 29 arc-minutes in size, but appears only 4% illuminated and sets at 10:25 PM. Tuesday’s moon shifts to western Cancer, 16° high, same size but 8% lit and sets at 11:03.

Mars and Venus also occupy western Cancer. Venus continues to be the brightest, blazing with minus 4th magnitude, 28 arc-seconds, 21° at 9:15 PM, 40% lit and sets at 11:18 PM. Red planet Mars is only 5° away from Venus, 1st magnitude, 4 arc-seconds, 94% lit, 24° high and sets at 11:29. Both occupy the same binocular and telescope field and are close to the Beehive star cluster (M44) on both nights. Southwestern Dwarf Planet 1Ceres still clings 8° from Leo’s tail, shines with 8th magnitude, 0.5 arc-seconds, 96% lit and sets at 1:58 AM.

The evening sky has a visitor; Comet C/2023 E1 was discovered in March and is now visible in our sky. It’s found 6° near the star Kochab in the Little Dipper (Ursa Minor), 67° lit, 10th magnitude and orbits the Sun in 85 years. What is unusual for this comet, is that it is circumpolar, which means that it circles the North Pole and does not rise or set. The comet is predicted to be at peak brightness next month. It is visible in small telescopes. Like planets and comets, asteroids have defined orbits about the Sun. Comets are ice and rock mixes, while asteroids are mostly rock. Comets sport tails behind them; the tails are a result of ices reflecting sunlight.

Saturn, in Aquarius, lights up the pre-Dawn sky with zero magnitude, 17 arc-seconds, rises at 12:23 AM in the Southeast and is 33° high at 4:15 AM. Sunday, Saturn was “stationary”, which means it appears to stop and back-up; the result of its orbit as seen from Earth. Neptune, 20° to Saturn’s left, glows with 8th magnitude, only 2 arc-seconds, rises in southeastern Pisces at 1:07 AM and 32° high at 4:15 AM.

Giant Jupiter shares eastern Aries with Uranus; glimmers with minus 2nd magnitude, a large 35 arc-seconds, rises at 2:38 AM and 12° at 4:15 AM; Wednesday, at 3:52 AM, the Great Red Spot is visible. Uranus, 14° from Jupiter, shimmers with 5th magnitude, 3 arc-seconds, rises at 3:12 and is 12° high at 4:15 AM. Northern Mercury brings up the rear, shining with 1st magnitude, 5 arc-seconds, rises at 4:30 AM, 82% lit but 2° above the horizon, observers must insure that they do not look at the Sun.