This is the Dudley Observatory Skywatch Line for Wednesday, April 27th and Thursday, April 28th written by Louis Suarato
The Moon sets at 9:50 a.m. Wednesday, and 10:44 a.m. Thursday, leaving the skies darker for your nighttime observing. In the north, you’ll notice Cassiopeia low early, becoming parallel with the horizon after midnight, before climbing counter-clockwise in the northeast. Ursa Major can be seen high above Cassiopeia, on the opposite side of Polaris, the North Star, with its Big Dipper seeming to pour stars down the northern sky. The stars curling around Polaris form the constellation Draco, the dragon. A deep sky object that can be seen in Draco is the Cat’s Eye Nebula, also known as NGC 6543. Discovered by William Herschel in 1786, NGC 6543 is a planetary nebula approximately 3,000 light years away. The Cat’s Eye Nebula appears as a fuzzy green-blue disk in amateur telescopes. The Hubble Space Telescope revealed its complex arcs illuminated by a central nucleus, providing the origin of its name. Look for the Cat’s Eye Nebula behind the head of the Dragon and below its back.
To the east of Draco, the constellation Hercules rises. As Hercules rises into the night sky, look for its Great Globular Cluster, M13. M13 consists of about 300,000 stars and can be found by first locating the four stars that comprise the body of Hercules, also known as the Keystone. You’ll notice one side of the Keystone is longer than the opposite side. M13 can be found by starting at the wider end of the Keystone and looking about one-third of the way from the imaginary line formed by the two top stars. Jupiter shines high above the southern horizon after 9:30 p.m. at an altitude of 55 degrees.
Mars rises at 10:20 p.m., followed by Saturn 30 minutes and about 10 degrees later. The 67% illuminated, waning gibbous Moon rises at 12:45 a.m. Thursday, in the constellation Sagittarius.
April 28 is the birth date of astronomer Bartholomeus Jan “Bart” Bok. Born in 1906, Bok, and his fellow astronomer and wife, Dr. Priscilla Fairfield, were known as the “salesmen of the Milky Way”. Their book “The Milky Way” was widely acclaimed as “one of the most successful astronomical books ever published.” Bok wrote “I have been a happy astronomer for the past sixty years, wandering through the highways and byways of our beautiful Milky Way.”