Night Sky Highlights for July-September 2021
Solar System
Perseid Meteor Shower
Peaking on the night of August 12-13
This should be a good year for the Perseids, because the crescent Moon sets at about 10:20pm on August 12, and after that many meteors should be visible if the sky is clear. If the weather is not good on that night, remember that quite a few Perseids can be seen for several days both before and after the peak night. Just lie back on a recliner or blanket, relax, and watch the show!
Mercury
Mercury makes an evening appearance after sunset in August and September, but its trajectory around the Sun keeps it low in the western sky for northern hemisphere observers. The best chance to spot it will be as soon as the sky darkens at the end of August and beginning of September.
Venus
As usual, Venus is the brightest object in the sky after the Sun and the Moon, and it will be a bright beacon in the western sky during evening twilight throughout the summer. Like Mercury, it takes a path that remains low in the west and southwest, so you need to look soon after sunset.
Mars
For months, Mars has been in the western sky during the evening hours. It continues to do so in July, but as the summer progresses it gets too close to the Sun to observe easily. It is also far from Earth and will present just a small disk through a telescope. From about July 8 to July 16, Mars and Venus will be just a few degrees apart ( 0.5 degrees apart on July 12 with a thin crescent Moon to the upper left).
Jupiter
This will be another good summer for observing Jupiter. It rises in the mid-evening during July, and it will be up most of the night in August and September.
Saturn
This will be a good summer for observing Saturn too. It will be in Capricornus, about 15 to 20 degrees to the west of Jupiter. It rises in the early evening in July, and will be up in the east as the sky darkens in August and September.
Uranus
Uranus is in Aries, rising after midnight in July, around midnight in August, and around 9 pm in September. At about magnitude 5.7, its blue-green disk is easy to see in any telescope. See the link below Neptune for a finder chart.
Neptune
Neptune is in Aquarius, slightly more than 20 degrees east of Jupiter and rising about an hour after Jupiter does. To find it, you will need a go-to scope or a finder chart such as the one in this article from the Sky & Telescope website:
www.skyandtelescope.com/observing/planets/ice-giants-neptune-and-uranus/
Deep Sky Objects
With the summer Milky Way overhead, there are so many deep-sky objects to choose from it is hard to know where to start. The list below includes some old favorites along with some lesser known but worthwhile targets.
Antares
Double star in Scorpius
If your telescope has good optics, this double star is a good challenge. The red magnitude 1.2 primary has a “greenish” secondary star of magnitude 5.4. The separation of the pair is just 2.9″, and because of the brilliance of Antares the secondary star can be very difficult to spot. With good seeing, it is a beautiful sight.
Messier 4
Globular cluster in Scorpius
Just 1.3 degrees to the west of Antares is the large and loosely packed globular cluster M4. It can be glimpsed with the naked eye under dark skies, and is easy to see with binoculars. With a medium-sized telescope, the stars are easily resolved, and a distinct chain of stars can be seen stretching across the cluster from north to south. Star-hop chart
Messier 80
Globular cluster in Scorpius
Through small scopes M80 is a hazy ball with a much brighter center. With medium to large scopes, many of the stars around the periphery can be resolved, making an impressive sight. The cluster is about 33,000 light years away and about 95 light years in diameter. Star-hop chart
Messier 5
Globular cluster in Serpens
This is one of brightest and most impressive globular clusters visible in the summer sky. It is just about as bright as the more famous M13 in Hercules. It is interesting to compare the two. The stars around the edges of both clusters are easy to resolve, but the core of M5 is denser and appears brighter. Star-hop chart
Messier 11, Wild Duck Cluster
Open cluster in Scutum
This is one of the richest open clusters in the entire sky, containing well over 1000 stars. Several hundred are visible through typical amateur telescopes in an area about half the diameter of the Moon. Through a small telescope or binoculars, it can appear as a V-shaped patch that vaguely resembles a flock of ducks in flight. Star-hop chart
Messier 16, Eagle Nebula
Diffuse nebula in Serpens
The first thing you will see when centering on M16 is a loose open cluster of fairly bright stars. Look more carefully, and you should start to see that this cluster is enveloped by a faint nebula. A nebula filter will help to see more. This is another Messier object that can be seen as a faint glow with ordinary binoculars. Star-hop chart
Messier 55
Globular cluster in Sagittarius
This is one more very nice example of a globular cluster for summertime viewing. To the east of the Sagittarius teapot shape, this cluster is large and bright with stars more loosely spaced in the center than those of M13. Star-hop chart
NGC 6543 (Caldwell 34), Cat’s Eye Nebula
Planetary nebula in Draco
At magnitude 8.1 the Cat’s Eye is one of the brightest planetary nebulae, and one of the best for viewing through amateur telescopes. It has a distinct blue-green color that is makes it hard to miss once it appears in the field of view. Once you have located it, switch to high magnification and see how much detail you can observe. Star-hop chart
NGC 6960 (Caldwell 34), Veil Nebula, western portion
Supernova remnant in Cygnus
The Veil Nebula is a remnant of a supernova that exploded several thousand years ago. It now covers an area of sky about 3 degrees wide, but it is very dim and you will need good dark skies to see it. An OIII filter makes a world of difference, making the nebula much easier to see with almost any scope. This part of the nebula appears to almost touch 4th magnitude 52 Cygni, so finding its location is not hard. Star-hop chart
NGC 6992-5 (Caldwell 33), Veil Nebula, eastern portion
Supernova remnant in Cygnus
Once you have found the western portion of the Veil (NGC 6960), slowly pan east about 3 degrees, and you should reach the large arching western segment. With a nebula filter, this part of the Veil shows a wealth of lacy detail. Through most scopes, it is too large to be seen all at once through a low-power eyepiece, so slowly pan across the field and take your time to see as much detail as possible. Star-hop chart
NGC 6822 (Caldwell 57), Barnard’s Galaxy
Irregular galaxy in Sagittarius
This small, irregular galaxy is a member of the local group of galaxies, and it is about 1.6 million light years away. Like the Veil Nebula, this galaxy is large but dim and diffuse. A nebula filter will not help here, but dark skies and a low-power eyepiece will give you the best chance of spotting this large oval glow. Star-hop chart