Venus and Jupiter, the brightest points of light in the night sky, dominate the early evening hours for most of the month. They are especially close together as the month begins, but remain close until late July. By the time they set, the two signature constellations of summer, Sagittarius and Scorpius, are in good view in the southern sky. The brightest stars of Sagittarius form a teapot, while those of Scorpius form the curved body and barbed tail of a scorpion.
This Week's Stargazing Tips
July 28: Dog Days
The “dog days” of summer are upon us. They get their name from the Dog Star, Sirius. The brightest star in the night sky, it is immersed in the Sun’s glare at this time of year. Because of that, ancient skywatchers named this period in the star’s honor.
July 29: Megrez
If not for its location, the star Megrez would attract little attention. It is not especially bright, but it is an important celestial “thumbtack,” connecting the bowl and handle of the Big Dipper.
July 30: Blue Moon
There’s a Blue Moon the next couple of months — the second full Moon in the month of July. Although that definition began as a mistake, it became popular more than two decades ago and has ingrained itself in skywatching lexicon.
July 31: The Swan
The swan climbs high across the southern sky on summer nights. It’s marked by its bright tail, the star Deneb, which is high in the east-northeast at nightfall. The swan’s body angles to the upper right of Deneb, while its wings flank the swan’s body.
August 1: Lammas
August 1 is the date of the ancient English festival Lammas. It is a cross-quarter day, which falls roughly half-way between a solstice and an equinox. Lammas marked the end of summer, not its mid-point.
August 2: 61 Cygni
After the Sun, the first star whose distance was accurately measured was 61 Cygni. It is part of Cygnus, the swan, which soars high overhead this evening. 61 Cygni is about 11 light-years away. It appears fairly close to Deneb, the swan’s tail.
August 3: Delta Cephei
Delta Cephei is one of the leading lights of Cepheus, the king, which stretches from north to northeast at nightfall. The star is unstable, so it pulses in and out like a beating heart. Astronomers recently discovered that it has a small, close companion star.
Check last week's tips if you missed a day.