Skywatch Line for Friday, August 4, through Sunday, August 6, 2023

This is Dudley Observatory’s Skywatch Line for Friday, August 4, through Sunday, August 6, written by Sam Salem.

On Friday, Sun rises at 5:50am and sets at 8:13pm; Moon sets at 9:13am and rises at 10:13pm.

Jupiter, at magnitude –2.4 in the constellation of Aries, rises a little after midnight in the east-northeast. By the beginning of dawn it shines very high toward the southeast.

Saturn, at magnitude +0.7 in dim constellation of Aquarius, rises in late twilight. It’s highest in the south in the couple hours before dawn.

Uranus, at magnitude 5.8 in Aries, is nice and high by the beginning of dawn, about 9 degrees left of Jupiter.

Neptune, at magnitude 7.9 at the Aquarius-Pisces border, rises after dark and is high in the south before dawn begins, about 20 degrees east of Saturn.

Look south soon after dark to locate the Rasalhague star, about equally far to the right of Altair and lower right of Vega. Altair is currently the Summer Triangle’s lowest star. Vega, the brightest, is nearly overhead. Rasalhague is the next-brightest star near the Summer Triangle, if you’d like to turn it into a quadrilateral. Rasalhague is the head of Ophiuchus, magnitude 2.1. The name, Rasalhague, is derived from an Arabic phrase meaning “the head of the serpent bearer”. Rasalhague is a binary star and the brightest star in the constellation of Ophiuchus, the serpent bearer.

The Big Dipper hangs diagonally in the northwest after dark. From its midpoint, look to the right to find Polaris, not very bright, glimmering due north. Polaris is the end of the Little Dipper’s handle. The only other Little Dipper stars that are modestly bright are the two forming the outer end of its bowl, second-magnitude star Kochab and third magnitude star Pherkad. On August evenings you’ll find them to Polaris’s upper left by about a fist and a half. Kochab and Pherkad are called the Guardians of the Pole, since they ceaselessly circle around Polaris throughout the night and throughout the year.

Look for the constellation Corona Borealis, also known as the Northern Crown. You’ll need a dark sky to see it. You’ll be looking high overhead during the evening hours.

The constellation is easy and distinctive. It makes the shape of the letter C. In the middle of the C is a white jewel of a star. This star, the brightest light in the Northern Crown, is called Alphecca or Gemma. The Crown is located roughly along a line between two bright stars. The first is the orange star Arcturus in the constellation Boötes the Herdsman. The second is beautiful, blue-white Vega in the constellation Lyra the Harp. Arcturus has already passed its highest point in the evening at this time of year and is slowly descending to the west. However, Vega is still high overhead in August evenings. Corona Borealis is closer to Vega.

A few Perseids trickle in starting in late July, then they build for a couple of days toward their peak, which this year is predicted for the night of August 12-13. The sky then will be moonless for perfect meteor-watching conditions. The weak, long-lasting Delta Aquariid shower is also somewhat active throughout this time.