Skywatch Line for Friday, October 6, through Sunday, October 8, 2023

This is Dudley Observatory’s Skywatch Line for Friday, October 6, through Sunday, October 8, written by Sam Salem.

On Friday, Sun rises at 6:58am and sets at 6:28pm; Moon sets at 3:01pm and rises at 11:30pm.

Mercury gets lower in the dawn. About 30 or 40 minutes before sunrise, look for it due east three fists at arm’s length or more to the lower left of high Venus. Mercury remains a bright magnitude –1.0.

Venus, brilliant at magnitude –4.7 in the constellation of Leo, is as high as it’s going to get as the “Morning Star.” Look east before and during dawn. Venus rises more than two hours before dawn’s first light, very far below Castor and Pollux. Watch Regulus, in the constellation of Leo, only 1 percent as bright, close in toward Venus from the lower left. They’re going to pass 2.3° from each other on the Monday morning. In a telescope, Venus is a thick crescent waxing on its way to its half-lit phase in late October.

Jupiter, at magnitude –2.8 in the constellation of Aries, rises in the east-northeast around the end of twilight. Watch for it to come up about 13° below the brightest stars of Aries. Jupiter dominates the eastern sky in late evening and shines highest in the south during the early-morning hours.

Saturn, at magnitude +0.6, in dim constellation of Aquarius, is the brightest star in the southeast in twilight. A month past opposition, it shines at a good height for telescopic viewing as early as 9 p.m. Fomalhaut twinkles two fists at arm’s length below it, and Altair shines four fists to Saturn’s upper right.

Watch for the short-lived Draconid meteor shower at nightfall and early evening on Sunday. You can watch through the night with the expected peak in the early morning of Monday. The Big Dipper sits low in the northwest. If you can spot it low in the sky, use the Big Dipper to star-hop to the star Polaris. Polaris marks the end star in the handle of the Little Dipper. Then you should also be able to spot Eltanin and Rastaban, marking the Draconids’ radiant point, high in the northwest sky at nightfall in early October. Draconid meteors radiate from near these stars, which are known as the Dragon’s Eyes. The 23% illuminated waning crescent Moon, on Sunday night, will not interfere with most Draconid meteors. Under a dark sky with no Moon, you might catch 10 Draconid meteors per hour. The Draconid shower is a real oddity in that the radiant point stands highest in the sky as darkness falls. Unlike many meteor showers, more Draconids are likely to fly in the evening hours than in the morning hours after midnight. This shower produces only a handful of slow meteors per hour in most years. In rare instances, fiery Draco has been known to spew forth many hundreds of meteors in a single hour.

The Draconids meteor shower’s parent comet responsible for the dust we see burning up in our atmosphere, is the small periodic comet 21P/Giacobini-Zinner. Michel Giacobini visually discovered this comet on December 20, 1900, in the evening sky, from the Nice Observatory in France. Comet 21P/Giacobini-Zinner comes about as close to the Sun as does Earth. Then it ventures back just past the orbit of Jupiter

before returning 6.6 years later. The International Cometary Explorer visited the comet in September 1985, making it the first comet to be visited by a space probe.