Skywatch Line for Friday, September 27, through Sunday, September 29, written by Sam Salem

This is Dudley Observatory’s Skywatch Line for Friday, September 27, through Sunday, September 29, written by Sam Salem.

On Friday, Sun rises at 6:49am and sets at 6:43pm; Moon rises at 1:20am and sets at 4:52pm.

On Friday, the waning crescent Moon will move close to the faint Beehive star cluster. In a dark sky, the Beehive is an easy target with binoculars. Look for them before morning twilight begins. On Saturday morning, the Moon will hang between the Beehive and Leo’s brightest star Regulus. They’ll rise a few hours after midnight.

Step out before or during early dawn Sunday morning, and look for 1st-magnitude Regulus 2° or 3° to the right of the waning crescent Moon,

The zodiacal light is a hazy pyramid of light. It’s sunlight reflecting off dust grains in the plane of our solar system. You need a dark sky to see it. Look east before dawn from about late August through early November. The best time to look is in a moonless sky, especially around a new Moon close to the September equinox.

Venus, magnitude –3.9, shines low in evening twilight. Starting 30 or 40 minutes after sunset, look for it gleaming above the west-southwest horizon. It sets before nightfall is complete.

Jupiter shines brightly in Taurus near the Bull’s horn-tip stars, Beta and Zeta Tauri. Mars this week is creeping across central Gemini. Watch for Jupiter to rise in the east-northeast around 11 p.m. Check for Aldebaran about a fist at arm’s length to Jupiter’s upper right. It remains to Jupiter’s upper right or right through the rest of the night.

Mars rises about an hour and a half after Jupiter, to its lower left. By the beginning of dawn, the two planets are very high toward the south-southeast.

Saturn, magnitude +0.7 in the constellation of Aquarius, is just a week or so past opposition. Look for it glowing in the southeast as the stars come out. It’s lower right of the Great Square of Pegasus, which is balancing on one corner. The Square’s upper-right edge points diagonally more or less to Saturn, two fists at arm’s length away.

Saturn climbs higher through the evening. It shines highest in south by midnight.

This is the time of year when the rich Cygnus Milky Way crosses the zenith about an hour after full dark. The Milky Way extends straight up from the south-southwest horizon, passes overhead, and runs straight down to the north-northeast. Cygnus floats, nearly straight overhead these evenings. Its brightest stars form the big Northern Cross. When you face southwest and crane your head way, way up, the cross appears to stand upright. It’s about two fists at arm’s length tall, with Deneb as its top.

Face south and look high after dark. The brightest star there is Altair, the southernmost point of the Summer Triangle. The other two are Deneb and Vega more nearly overhead. A marker for Altair is always its little neighbor Tarazed (Gamma Aquilae), currently a finger-width at arm’s length to Altair’s upper right. Barely a fist at arm’s length

above Altair, high look for the faint little constellation Sagitta, the Arrow. The Arrow points toward upper left. It is 4½° long from tail-feathers to tip, easily fitting into the field of view of most binoculars