This Week’s Sky at a Glance, 2022 July 9 – 16 ~by Curt Nason
Galaxies are favourite targets for amateur astronomers and many are visible with just binoculars. Two are seen easily with the naked eye in the southern hemisphere: the Large and Small Magellanic Clouds. The Andromeda Galaxy is a naked-eye blur for rural New Brunswickers and it looks majestic in binoculars. But there is one galaxy that is spectacular regardless of your location or observing equipment, and that is our home galaxy.
The Milky Way is at least 110,000 light years across, and although it is composed of perhaps 400 billion stars we can distinguish only about 4000 as individual stars from a rural area. The Sun is 27,000 light years from the galactic core, within a spur between the inner Sagittarius and outer Perseus spiral arms. When we look above the spout of the Sagittarius Teapot asterism we are looking toward the galactic core, but vast clouds of dust hide the stars between the spiral arm and the core. South of the head of Cygnus the Swan we see the Milky Way split in two by the Great Rift, one of those dust clouds.
Star formation occurs in clouds of gas and dust within the spiral arms and some can be seen as bright patches with binoculars. Just above the spout of the Teapot is M8, the Lagoon Nebula; and a hint of M20, the Trifid Nebula, can be seen in the same field of view above. Scanning to the upper left up the Milky Way you encounter M17, the Swan (or Omega) Nebula; and star clusters M16 in the Eagle Nebula and M11, the Wild Duck Cluster. A tour of the Milky Way under a dark sky can keep a binocular stargazer engaged for an evening.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 5:37 am and sunset will occur at 9:10 pm, giving 15 hours, 33 minutes of daylight (5:45 am and 9:12 pm in Saint John). Next Saturday the Sun will rise at 5:43 am and set at 9:06 pm, giving 15 hours, 23 minutes of daylight (5:51 am and 9:08 pm in Saint John).
The Moon passes above the orange supergiant star Antares in Scorpius on Sunday, and it rises below Saturn late Friday evening. The Moon is full and at perigee on Wednesday, so expect to see extreme tides later in the week. With Saturn rising around 10:30 pm and Jupiter just after midnight, it won’t be long before amateur telescopes will be pointed their way again in mid-evening. Mars and Venus grace the early morning sky to the east, bracketing the Pleiades and Hyades star clusters of the winter constellation Taurus. Mercury is out of sight, passing behind the Sun next weekend.
On Sunday evening at 8 pm, tune in to the Sunday Night Astronomy Show via the Facebook page or YouTube channel of Astronomy by the Bay.
Questions? Contact Curt Nason.