What's Up in the Night Sky

August 2025 - Vol. 29, No. 8

This Month's Night Sky - NOTE: The next paragraph describes the sky as it appears at 10 pm EST (11 pm EDT) near mid- month. The sky also looks this way at 11 pm EST (midnight EDT) during the beginning of the month and at 9 pm EST (10 pm EDT) by month's end.

Bright blue-white Vega (Lyra) shines high overhead as it "leads" the Summer Triangle across the night sky. The "Triangle" is the summer’s most prominent asterism and is made up of three stars: Vega, the brightest, Deneb (Cygnus) and Altair (Aquila). Scorpius and the bright star Antares occupy the southern sky. Look for another famous asterism, "the teapot" (Sagittarius). The stars of constellations Scorpius and Sagittarius, embedded in the "Milky Way" (part of one of the spiral "arms" of our galaxy), are at their best this month.

MERCURY, starts the month at inferior conjunction, entering the morning sky, best seen from the northern hemisphere. VENUS, in the morning sky, has a nice conjunction with Jupiter on the 12th. MARS, visible in the evening sky, shines at +1.6 magnitude in Virgo. JUPITER rises in the morning sky, shining at -2.0 magnitude by month's end. SATURN rises in the evening sky. URANUS rises around midnight with the constellation Taurus. NEPTUNE rises in the evening sky. (You'll need a telescope to observe Neptune.)

Review how to determine Angular Measurement.

Calendar of Events

NOTE: For those observers not in the ET zone, convert the calendar times to your zone's time by subtracting one hour for CT, two for MT and three for PT. Don't forget to adjust for Daylight Savings Time when necessary by subtracting one hour from your planisphere's time. Dawn and dusk times must also be corrected. See your local newspaper, TV news, or cable TV's Weather Channel for sunrise and sunset times or check with the U.S. Naval observatory. Unfortunately some of these events may occur during daylight hours in your area.

DATE	EVENT
01	Mercury in inferior conjunction. Moon at apogee.
02	Venus 2 deg. S. of M-35 open star cluster.
04	Mercury at greatest heliocentric lat. S. Alpha Scorpii, Antares, 0.6 deg. N. of Moon, occultation from S. Polynesia, New Zealand, S. tip of South America, parts of Antarctica.
06	Saturn 1.1 deg. S. of Neptune.
08	Pluto, 0.01 deg. S. of Moon, occultation from E. Polynesia, NW S. America, S. Caribbean.
09	August's full moon is often called the " Sturgeon Moon" because it is the time of year that lake sturgeon were very abundant and easy to catch in the Great Lakes and Lake Champlain in North America. Unfortunately, they are nearly extinct today. Conservation efforts are helping to restore their numbers.
10	Mercury stationary.
12	The Perseid meteor shower peak will be affected by the bright Moon, just thre days after full. Venus meets up with Jupiter in the constellation of Gemini for a splendid conjunction when the two are less than a degree apart. Watch the two planets for a few nights either side of the conjunction. Saturn 4 deg. S. of Moon. Neptune 3 deg. S. of Moon.
14	Moon at perigee.
16	Moon 0.9 deg. N. of the Pleiades star cluster (M-45).
19	Mercury at greatest elongation W. (19 deg.) Mercury 2 deg. S. of the Beehive cluster (M-44) Jupiter 5 deg. S. of Moon.
20	Venus 5 deg. S. of the Moon.
21	Moon 2 deg. N. of the Beehive cluster (M-44) Mercury 4 deg. S. of Moon.
26	Mars 3 deg. N. of Moon.
27	Alpha Virginis, Spica, 1.2 deg. N. of Moon, occultation from S. tip of South America, W. Antarctica.
28	Mercury at perihelion.
29	Moon at apogee.
31	Alpha Scorpii, Spica, 0.7 deg. N. of Moon, occultation from SE edge of S. Africa, S. Madagascar, Kerguelen Is., most of Antarctica, S. New Zealand.

Lunar Almanac for June 2025

Phases of the Moon	Phase and Date(s)	Best viewed before local midnight
	New 23	Deep Space Objects
	1st. Qtr 01 & 31	Planets & Moon
	Full 09	Moon
	Last Qtr 16	Deep Space & Planets

Topic of the month: Cygnus, the Swan

During the month of August, the constellation of Cygnus, the swan, dominates the night sky and the summer Milky Way. High overhead after darkness chases away the long summer twilight, the swan flies. The brightest star of the constellation is Deneb, a blue giant that is among the 20 brightest stars in the night sky. A blue giant star, Deneb is designated Alpha Cygni and forms a large triangle known as the Summer Triangle with the bright stars Vega and Altair.

The constellation is thought to resemble a bird. Because it is so far north, it spends a lot of time in the northern sky, visible all year round from northern locations. (Although it may not be visible all night.) If you have trouble seeing a bird, you may resonate with Cygnus's other identify, the constellation is often called the Northern Cross. If you watch the cross all night in August from the northern hemisphere, you will notice that it twists in the sky, so that by the time it sets, it appears to hang upright over the western horizon. It is rather fascinating that the cross will be in this position in the inky evening sky on December 25.

Another beautiful star in the constellation is Beta Cygni, known as Albireo. Albireo is a beautiful double star. In a small telescope the stars appear bright yellow and blue. The pair may also be split with binoculars. The central star of the Northern Cross is the second-magnitude star, Sadr, interesting to view in a small telescope. The star fields of the Milky Way between Albireo and Sadr are magnificent. Notable galactic clusters in Cygnus include M29, M39, NGC 6819 and NGC 6866.

The Milky Way in the constellation of Cygnus offers much in the way of bright and dark nebulae, for it is here that the "Great Rift" of the Milky Way begins. This rift is the same dark lane that we can observe in distant spiral galaxies, for the dark material of the rift absorbs light from the stars. It is composed of gas that someday may form new stars in our galaxy. For deep sky observers, Cygnus offers one of the finest supernova remnants known as the Veil Nebula. The star that formed this magnificent nebula exploded over 5,000 years ago, its spreading debris field now covers over 3 degrees of the sky for Earth based observers. This expanding wreath of gas has two separate designations, NGC 6960 and NGC 6992. The western portion of the veil (NGC 6960) is located near the star 52 Cygni while the eastern portion displays fabulous filamentary structure. For bright nebulae, Cygnus offers NGC 7000, the North American Nebula approximately 3 degrees E of Deneb. So called for it's resemblance to the continent, this bright field may be noted with the naked eye at a dark site. It is often seen in binoculars and a small telescope will yield its brightest jewels.

--See You Under the Stars!
Astra for Astra's Almanac

The star chart above was generated by Stellarium, a free open source planetarium program. The above image was created by Dawn Jenkins, using Stellarium and a graphic editing program to format the image for this web page. Editing was done for educational purposes only. Stellarium offers much more to amateur astronomers and is being used in planetariums and to guide telescopes in the field. Simple charts like the one above can be used on the internet for non-profit, illustration purposes. Proper credit is due of course! Thank you to the makers of this fine program from Astra's Star Gate.