Sky at a Glance 2020 May 2 – 9

Photo showing the constellation Hercules with the keystone asterism located between the bright stars Vega and Arcturus

This Week’s Sky at a Glance, 2020 May 2 – 9 ~by Curt Nason

I was fascinated by the movie Hercules, starring bodybuilder Steve Reeves, which I saw one Saturday afternoon at the Vogue theatre in McAdam sometime in the early 60s. I was nurturing my interest in the sky at that time so the constellation of Hercules has long been a part of my life. These spring evenings it is in the east as twilight fades.

Look for a keystone asterism one third of the way from the bright star Vega toward equally bright Arcturus; that is the upside-down body of the legendary strongman. Hercules is usually depicted down on his right knee, with his left foot on the head of Draco the Dragon and his head close to that of Ophiuchus. Originally the constellation was called The Kneeler, and the star at his head is called Rasalgethi for “head of the kneeler.” It is the alpha star of the constellation, although Kornephoros (the club bearer) is brighter.

With binoculars you can pick out two globular clusters from the Messier catalogue in Hercules. Globular clusters are ancient compact groups of typically tens-to-hundreds of thousands of stars that orbit our galaxy’s core. One third of the way from the top right star of the Keystone to the bottom right star is M13, perhaps the finest globular cluster in the northern hemisphere. A line from the bottom right star through the middle of the top of the Keystone, and extended about an equal distance, will put you in the area of M92, one of the oldest objects in our area of the galaxy at more than 13 billion years.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 6:03 am and sunset will occur at 8:29 pm, giving 14 hours, 26 minutes of daylight (6:10 am and 8:32 pm in Saint John). Next Saturday the Sun will rise at 5:53 am and set at 8:38 pm, giving 14 hours, 45 minutes of daylight (6:01 am and 8:41 pm in Saint John).

The Moon is full on Thursday; the Milk, Planting or Frog Croaking Moon. Brilliant Venus is still setting after midnight, while Mercury is at superior conjunction on Monday. The two inner planets will be crossing paths in a few weeks. Jupiter and Saturn retain their 5 degree physical distancing in the morning sky, but soon they will start to separate. Mars rises after 3 am, about 75 minutes after two gas giants. If you are out early on Wednesday you might catch a few meteors from the Eta Aquariid shower coming out of the south, although bright moonlight will wash out the fainter ones.

Saturday is International Astronomy Day, and you can cap off Astronomy Week with the local Sunday Night Astronomy Show at 8 pm.

Questions? Contact Curt Nason.

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