Skywatcher's Guide written by: Lucas Snyder (Flandrau Planetarium Specialist)
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Stars and Constellations
In August we can still see part of the spring sky at the beginning of the night after sunset. The bright star Spica in the constellation Virgo is low in the west-southwest. A little higher in the west is even brighter Arcturus in the constellation Boötes. The easily recognizable Big Dipper (Ursa Major) is also visible in the northwest. You can use two stars in the end of the bowl to find Polaris, the north star, which is the end of the handle of the Little Dipper (Ursa Minor). Next, high in the middle of the sky we see the summer constellations, with the three bright stars of the Summer Triangle being the most prominent. Vega is the highest and brightest of the three, with Deneb below towards the east and Altair to the southeast. Then Scorpius with the bright star Antares is visible to the south-southwest, and the "teapot" of Sagittarius is nearby towards the south. The summer Milky Way is prominent this time of year stretching all the way across the sky from south-southwest to north-northeast. Next, the fall sky is beginning to rise in the east at the beginning of the night. The "great square" of Pegasus is low towards the east and Andromeda is adjacent to the northeast. Cassiopeia is a little higher in the northeast, and appears as a "W" this time of year.
In September, Boötes is now low in the sky towards the west-northwest. The Big Dipper is also very low in the northwest. Polaris and the Little Dipper are of course still in the North. Now Scorpius is low in the southwest, and we can see the Sagittarius "teapot" in the south-southwest. The Summer Triangle is still up in the middle of the sky, and the summer Milky Way is still a prominent streak across the sky. Next, Pegasus and Andromeda are higher in the east, and you might be able to find the Andromeda Galaxy. Cassiopeia is higher in the northeast and is starting to rotate to a "3" orientation. Finally, below that you may see Perseus along the horizon at the beginning of the night.
Interesting Stars Visible in August and September (from 7 to 10 pm)
| Name / Designation | Apparent Magnitude (lower = brighter) | Distance (light-years) | Notes |
|---|---|---|---|
| Arcturus | -0.05 | 36.7 | |
| Vega | 0.03 | 25 | |
| Altair | 0.76 | 17 | |
| Spica | 0.98 | 262 | |
| Fomalhaut | 1.16 | 25 | |
| Markab | 1.25 | 140 | |
| Deneb | 1.25 | 3230 | |
| Polaris | 1.97 | 431 | |
| Alpheratz or Sirrah | 2.07 | 97 | |
| Mirach | 2.07 | 199 | |
| Algol | 2.09 | 93 | variable star |
| Denebola | 2.14 | 36.2 | |
| Enif | 2.38 | 670 | |
| Almak | 2.1 / 5.0 & 6.3 | 355 | triple star system w/ 64 yr orbit |
| Albireo | 3.2 / 5.8 & 5.1 | 390 / 380 | possibly a triple star system |
| Eta Cassiopeiae | 3.5 / 7.4 | 19 | 480 yr orbit |
Solar System
Mercury is visible in the morning sky for the first half of August, but then passes behind the Sun around the end of the month. It will not emerge in the evening sky until the very end of September.
Venus is visible in the evening sky for all of August and September, low in the west-southwest.
Mars is getting higher in the east before sunrise, moving from Taurus, all the way through Gemini and into Cancer.
Jupiter rises in the morning sky in mid-August, getting a little higher each day. It is moving from Cancer to Leo.
Saturn rises a little earlier each evening, eventually coming up at sunset by the end of September. It is near the border of Pisces and Cetus.
Calendar of Night Sky Events
| Date | Event |
|---|---|
08/02/26 | Mercury at greatest western elongation. — Visible before sunrise. |
08/05/26 | Last Quarter Moon. |
08/12/26 | New Moon and Total Solar Eclipse — Not visible from Tucson. |
08/12/26 | Peak of Perseids meteor shower. |
08/14/26 | Venus at greatest eastern elongation. — Visible after sunset. |
08/15/26 | Appulse of Mercury and Jupiter — Separated by 0.6°. |
08/19/26 | First Quarter Moon. |
08/27/26 | Mercury at superior conjunction. — Passing behind the Sun. |
08/27/26 | Full Moon and Partial Lunar Eclipse. — Visible from Tucson. |
09/04/26 | Last Quarter Moon. |
09/10/26 | New Moon. |
09/18/26 | First Quarter Moon. |
09/22/26 | Earth at Southward Equinox. — Beginning of our Fall. |
09/25/26 | Neptune at opposition. — Best time to see our farthest planet. |
09/26/26 | Full Moon. |
Deep Sky
There are many deep sky objects we can see since the summer Milky Way is high in the sky. There are many open star clusters that can be seen with only binoculars scanning this part of the sky. For example we have the Butterfly Cluster (M6) and Ptolemy's Cluster (M7) near the tail of Scorpius. Further north there is the Wild Duck Cluster (M11) in the faint constellation of Scutum between Sagittarius and Aquila. There is also the asterism of the Coathanger between Aquila and Cygnus in the fainter constellation of Vulpecula. Next, heading towards the west we can see the Coma Star Cluster in the constellation of Coma Berenices, which is even visible naked-eye. The Pleiades (M45) will be visible later in the night, after midnight.
There are a several globular clusters we can see as well, as the center of our galaxy is the highest it gets for the year. Near the bright star Antares in Scorpius lies the globular cluster M4. In Sagittarius we also have the Teapot Cluster (M22). Of course we have the famous Hercules globular (M13) high in the east. Also, M15 is visible in the east near the head of Pegasus.
For nebulae, we have several in the plane of the galaxy, one of which is the Swan Nebula (M17) in Sagittarius, also known as the Omega Nebula. There is also the Lagoon Nebula (M8) nearby and the North America Nebula (C20) further north in Cygnus. For planetary nebulae we have the Ring Nebula (M57) in Lyra, the Dumbell Nebula (M27) in Vulpecula, and the Blue Snowball (C22) in Andromeda.
And now the galaxies: Although the Big Dipper is getting lower in the sky, you may still be able to find some of the galaxies in this part of the sky. We have the Whirlpool Galaxy (M51) and the Pinwheel Galaxy (M101) near the handle, and the Cigar Galaxy (M82) and Bode's Galaxy (M81) near the bowl. The spectacular Andromeda Galaxy (M31) is now coming up in the northeast, along with the nearby Triangulum Galaxy (M33).
Interesting Deep Sky Objects to Observe during August and September (from 7 to 10 pm)
| Designation | Name | Apparent Magnitude | Apparent Size | Distance (light-years) | Type |
|---|---|---|---|---|---|
| Messier 31 | Andromeda Galaxy | 3.4 | 3° x 1° | 2,900,000 | spiral galaxy |
| Messier 33 | Triangulum Galaxy | 5.7 | 67' x 42' | 3,000,000 | spiral galaxy |
| Messier 3 | (in Canes Venatici) | 6.2 | 18' | 34,000 | globular cluster |
| NGC 7293 | Helix Nebula | 7.3 | 16' | 450 | planetary nebula |
| Messier 27 | Dumbbell Nebula | 7.4 | 8' × 6' | 1,250 | planetary nebula |
| NGC 7009 | Saturn Nebula | 8 | 36" | 2,400 | planetary nebula |
| Messier 81 | Bode's Galaxy | 8.5 | 21' | 1,200,000 | spiral galaxy |
| Messier 57 | Ring Nebula | 8.8 | 1' | 2,300 | planetary nebula |
| Messier 82 | Cigar Galaxy | 9.5 | 14' | 1,200,000 | galaxy |
Frequently Asked Questions
What is light pollution, and why is it a problem?
You’ve probably heard the term light pollution before, most likely in the context of astronomy. It is certainly a concern for astronomers, but it affects everyone to some extent. Light pollution in general is any degradation of natural darkness caused by excessive, unwanted, or misdirected light. This usually refers to the collective light of large cities, but can even refer to a single inappropriately used lightbulb. Astronomers are concerned with light pollution because the night sky is their laboratory. Any stray light can alter measurements of the faint objects they are studying. Even for astrophotographers and casual stargazers, unwanted light can wash out what you’re trying to see, decreasing contrast and blurring details.
Beyond astronomy, light pollution has environmental effects, disrupting circadian rhythms for a wide range of species, including humans. For some species it can be not only disruptive, but detrimental, interfering with hunting or mating, and leading to population decline. Even plants are affected, as their day/night and seasonal cycles get thrown off by artificial light.
Another thing to think about is the energy cost of all the excess light being produced. Every watt of energy used has to come from somewhere, whether that be from renewable resources or not. But wasted light equals wasted energy (potentially contributing to other kinds of pollution), and probably wasted money as well.
So what can we do about it? On an individual basis, we can make sure we are not producing more light than we need. Consider putting motion sensors or timers on your outside lights so they are only on while being used. Also, you don’t always need the brightest light available. Often just a dim light is enough to help you see what you need to see. Plus you should make sure that your light is shielded, so it only goes where it is intended. A bare lightbulb shines in all directions including up into the sky where it adds to the overall light pollution of your neighborhood and your city.
On a bigger scale, cities can establish lighting codes that limit lighting in commercial and industrial areas. They can also be smarter about lights along streets and other public areas. There is an organization called DarkSky International (headquartered in Tucson!) that works to educate the public, work with governments, and recognize places that set good examples of responsible lighting.
If you have any questions you'd like me to answer in the next issue of SWG, please let me know. I'm also happy to take suggestions or comments, and also pictures if you'd like to send them. Happy viewing!
Date of publication: 2026