This Week’s Sky: August 19 – 26

The waning Moon visits the Hyades and Aldebaran in Taurus.

A meteor streaks by the dark nebula known as Barnard’s E and 2.7-magnitude Gamma Aquilae. Photo by Gary Seronik

All Week

South 1hr after sunset

The view facing south, one hour after sunset.

It’s a three-planet week for solar system fans. Two planets are evening objects, and one is on display at dawn. The evening pair are Jupiter and Saturn—both well placed as twilight fades. Jupiter, gleaming at magnitude –2.3 is likely will be the first star-like dot you notice at dusk. In the waning stretch of its current apparition, the giant planet now culminates at sunset. If you want to inspect its cloud belts, Great Red Spot and quartet of bright moons, the earlier you train your scope on Jupiter, the better. Saturn, on the other hand, isn’t at its best until slightly before 10:30 p.m., local daylight time. Shining at magnitude 0.3 from eastern Sagittarius easily outshines the trio of naked-eye stars just above it. The rings are tilted “open” at nearly the maximum angle possible, making the famed feature an easy target in any telescope. Finally, we have a solitary dawn planet that’s a bit of a challenge to view. Mercury glows at magnitude –1.2 and reaching the end of a favourable morning apparition. It rises a little more than one hour ahead of the Sun, so an unobstructed east-northeast horizon will be a big help when it comes to spotting this fast-moving, little world.

August 23

The Moon reaches last-quarter phase today at 10:56 a.m., EDT. The best time to observe it in your scope, however, is around 6:00 a.m., local daylight time, when the Moon rides high in a twilight sky.

August 24

The Moon and Hyades cluster as seen in 10×50 binoculars.

Soon after the Moon rises in the early morning hours, you can watch it slowly drift through the Hyades cluster in Taurus. Indeed, the sooner you look, the closer the Moon will be to the cluster stars. Observers on the East Coast get the best view, while those on the West Coast will have to content themselves with watching the Moon exit the Hyades, though still positioned 1½ degrees from first-magnitude Aldebaran. No matter where you’re located, the conjunction will be a fine binocular sight. (For more on this event, turn to page 25 of the July/August issue of SkyNews.)

Weekend Stargazer

Dark Nebula chart

Use this chart to identify the Northern Coal Sack and Barnard’s E.

Evenings over the August 23 – 25 weekend are free from moonlight. That, combined with the season’s mild temperatures, make this a fine time for poking around the Summer Milky Way. If you’re in a location free from significant light pollution, take a moment to check out some dark nebulas. Provided you can see the Milky Way really well from your observing site, these opaque clouds of interstellar dust and gas deserve a place on your deep-sky hit list. Two of the finest examples are well placed for viewing this weekend.

When you look along the band of the Milky Way, you’ll notice numerous dark rifts and patches. One conspicuous area, known as the Northern Coal Sack, hides in the celestial weeds southeast of 1.2-magnitude Deneb, the brightest star in Cygnus. This feature is part of a much larger dark assemblage known as the Great Rift, which bisects the summer Milky Way for much of its length. You don’t need a telescope to spot the Northern Coal Sack—just a dark sky. In fact, it’s so big that even binoculars diminish its appearance.

Another well-known dark nebula is Barnard’s E, located a few degrees northwest of 0.9-magnitude Altair, the brightest star in Aquila. This time, get out your binos (or a small, wide-field telescope) and look for a ragged, E-shaped blackish blob about one degree due west of 2.7-magnitude Gamma (γ) Aquilae. Observing the ghostly E takes some getting used to, but once you train your eye to look for an absence of starlight, you’ll be surprised at the number of other dark nebulas you can pick up with binoculars.

At SkyNews we love to read about your experiences and see your photos. You can share them with us by e-mailing [email protected].

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