Night Sky Highlights for July-September 2017
Perseid Meteor Shower
This great annual meteor shower peaks around Saturday, August 12, but the many Perseids can be seen throughout the week of August 10-16. During this week, the waning gibbous Moon will be rising late in the evening, and then shortly after midnight, so the best times to see meteors may be in the evening soon after dark.
Monday, August 21
In Connecticut, this will be a partial eclipse, with about two-thirds of the Sun covered at its maximum. However, the path of totality stretches across the entire US, and many ASHN members will be going to these locations in the hope of seeing a spectacular total eclipse. Hoping for clear skies!
This elusive planet makes a brief appearance in the western sky after sunset in late July and early August, and it will be farthest from the Sun on July 29. Mercury also appears in the morning sky for a few days around September 12.
Brilliant Venus can be seen in the eastern sky before dawn throughout the summer months.
This is not a good time to view Mars. It will be close to the Sun during July and August. By September, Mars will be rising in the east shortly before dawn. On September 16, it will be about 0.3 degrees below Mercury, but this pair will probably be difficult to see with the naked eye in the bright pre-dawn sky.
Jupiter and Saturn
These two planets will dominate the evening sky throughout the summer months. Jupiter will be the brightest object in the southwestern sky (in Virgo), and Saturn will be in the southeastern sky (in Scorpius and Sagittarius). Both of these will be well positioned for telescope viewing.
Uranus is in Pisces, rising around midnight in July, and then rising in the early evening by September. If you try to spot it with a telescope, this article from the Sky & Telescope website includes finder charts for both Uranus and Neptune:
This gas giant is in Aquarius this year, and it will be rising late in the evening during July. Neptune will be at opposition on September 4 (rising just as the Sun sets), so it will be conveniently placed for telescopic observing in the eastern sky once it gets dark.
Deep Sky Objects
Summer is an ideal time for looking into the deep sky, and you don’t need an enormous telescope to do so. Below is a list of some objects that are large and bright enough to be fine targets for binoculars or small telescopes.
Messier 6, the Butterfly Cluster
Open cluster in Scorpius
About half-way between the tail of Scorpius and the teapot of Sagittarius, Messier 6 is an excellent open cluster to view on a clear dark night. Through a telescope, this cluster really does look like the outstretched wings of a butterfly. Can you see the bright red-orange star (a red giant) on the tip of one of the butterfly’s wings?
Messier 7, Ptolemy’s cluster
Open cluster in Scorpius
This bright cluster is not very hard to see with the naked eye if you know where to look, even from Connecticut, where it is low in the southern sky, just a few degrees to the lower left of Messier 6. It has been known since ancient times, first recorded by Claudius Ptolemy. Many blue-white stars can be seen through binoculars or a telescope at low power.
Messier 8, the Lagoon Nebula
Diffuse nebula with open cluster in Sagittarius
This nebula is also pretty easy to see with the naked eye as a fuzzy spot above the spout of the Sagittarius teapot. The hazy nebula is very easy to see through binoculars, and the open cluster NGC 6530 can be seen on its eastern edge. The view is quite impressive through a telescope with a wide-field eyepiece.
Messier 17, the Swan Nebula
Diffuse nebula in Sagittarius
This is a bright emission nebula that has the shape of a swan floating on a pond in profile. Other nicknames are the Checkmark, Omega, or Horseshoe Nebula. Its shape can even be seen in binoculars, and it does look something like a check mark.
Globular cluster in Sagittarius
Through binoculars, Messier 22 is easy to spot just to the upper left of the star that marks the top of the Sagittarius teapot, appearing as a hazy ball. M22 is fairly nearby and appears quite large, and even with a telescope of modest size, some of its stars can be resolved if you have a dark location and a clear sky.
Messier 24, the Sagittarius Star Cloud
Milky Way star cloud in Sagittarius
Some sections of the Milky Way are especially good for observation through binoculars or a small telescope, and Messier 24 is one of them. It is visible to the naked eye as a small cloud, about 3 times the apparent size of the Moon, and about 5 degrees above the lid of the Sagittarius teapot. Rich clouds of countless stars can be seen through a telescope.
Double star in Cygnus
One of the most famous and colorful double stars, Albireo marks the head of Cygnus the Swan. Identifying colors can be subjective, but the components are often described as orange and blue. It may be hard to separate the pair with low-power binoculars, but the smallest telescope will do the job.
Collinder 399, the Coathanger Cluster
Asterism in Vulpecula
Also known as Brocchi’s Cluster, this group of about 10 bright stars is best viewed through binoculars because it covers more than 1 degree of sky. However, it does look good through a small telescope at low power. At magnitude 3.6, it can be seen with the naked eye, about 5 degrees to the west of the arrow shape of Sagitta.
Messier 27, the Dumbbell Nebula
Planetary Nebula in Vulpecula
The arrow shape of Sagitta can also help to guide you to the Dumbbell Nebula, as it is just 3 degrees north of the tip of the arrow. This is one of the largest and brightest planetary nebulas in the sky. Through binoculars it appears only as a small smudge of light, but through a telescope its distinctive hourglass shape can be seen quite easily.