This Week’s Sky at a Glance, April 29 – May 6 ~by Curt Nason
The constellation Hercules is up in the east after sunset, recognizable by the Keystone asterism that forms the legendary strongman’s body. He is usually pictured kneeling upside down in the sky, having a tête-à-tête with Ophiuchus the Serpent Bearer, with his foot placed triumphantly on the head of Draco the Dragon. The Keystone is situated two-thirds of the way from Arcturus to Vega.
Hercules (Heracles in Greek mythology) was the result of one of Zeus’s many affairs with a mortal woman. Consequently, Hera (wife of Zeus) did whatever she could to have Hercules killed. As a baby Hercules strangled two snakes sent by her, and the Twelve Labours he performed were assigned by King Eurystheus, a representative of Hera.
Two globular clusters, M13 and M92, can be seen with binoculars in the constellation. M13, the finest globular cluster in the northern hemisphere, is along the right side of the Keystone, two-thirds of the way from bottom to top. A line from the bottom right star of the Keystone to the middle of the top side, and extended not quite that same distance, will put you near M92. Currently there are comets near both feet of Hercules, bright enough to be seen in a small scope or perhaps in binoculars with a dark sky. Comet 41P/Tuttle-Giacobini-Kresak is near the left foot by Draco’s head, and C/2015 V2 Johnson is near the right foot past the knee of Hercules. See the Comets section of the Heavens-Above website for their current locations.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 6:08 am and sunset will occur at 8:24 pm, giving 14 hours, 16 minutes of daylight (6:15 am and 8:27 pm in Saint John). Next Saturday the Sun will rise at 5:58 am and set at 8:33 pm, giving 14 hours, 35 minutes of daylight (6:04 am and 8:36 pm in Saint John).
The Moon is at first quarter on Tuesday, giving great views in a scope all week. Jupiter is highest in the south around 11:30 pm. On Wednesday evening, with a scope or even binoculars, you can watch its volcanic moon Io approach and finally disappear behind the planet at 11:11 pm. Late the next evening Io will be in nearly the same position, having emerged from a transit in front of Jupiter at 10:39 pm. Mars approaches the Hyades star cluster, which is anchored on one side by orange Aldebaran, and sets around 10:45 midweek. Venus is at its brightest for its current morning apparition on Sunday, while later in the week Mercury rises 45 minutes before the Sun. By midweek Saturn is rising before midnight.
To cap off Astronomy Week RASC NB members in Moncton will be holding public observing at the soccer field next to Lou MacNarin School from 9-11 pm on Friday, April 28; solar observing at that location Saturday, April 29, from 9 am to 1pm, and observing at the Moncton High School Observatory from 9-11 pm that evening. In Saint John, members are holding public observing at the Rockwood Park Bark Park (Fisher Lakes entrance) from 9-11 pm on Saturday, April 29, with Sunday as a back-up date if it is cloudy.
Questions? Contact Curt Nason.