Sun rises at 5:47am
Sun sets at 6:49pm
Moon phase: Third Quarter, Waning Gibbous
Moon rises at 9:51pm
Moon sets at 10:02am
The Summer Triangle
Ah those summer nights! Get outdoors and enjoy them; it’s cool and clear, the stars are out and the night sky is calling. More than any other month, July is the month of the Summer Triangle. It’s out from dusk till dawn, like teenagers, dancing across the darkness. The Summer Triangle shines high overhead in the middle of the night, and sparkles in the west as the rose-coloured dawn begins to colour the sky.
After sunset, look eastward to see Vega, Deneb and Altair – they are the first three stars to light up the eastern half of the sky after dusk, and their bright and sparkling radiance is even visible on a moonlit night or in light-polluted cities.
The Summer Triangle is large on the celestial dome. Extend your hands out in front of you, with fingers spread, and touch the thumbs together. The span from little finger to little finger is about the same as the range from the star Vega to the star Altair. And a single outstretched hand more or less fills the gap between Vega and Deneb.
Try looking first for the most prominent star in the eastern sky, this is Vega in the constellation Lyra, the Harp. Vega is blue-white in colour. It’s sometimes called the Harp Star. And many people recognize the constellation Lyra as a triangle of stars connected to a parallelogram.
The star Deneb is the northernmost star in the Summer Triangle. Its constellation is Cygnus the Swan. In a dark sky, you might be able to see that Cygnus is flying along the starlit trail of the summer Milky Way.
The third star in the Summer Triangle is called Altair, and it’s the brightest star in the constellation Aquila the Eagle. This is the bottom star of the Summer Triangle; that is, it’s the last of these three bright stars to ascend over the horizon.
In Asian cultures, Altair and Vega figure in one of the most beautiful of all stories in the night sky. In Japan, for example, Vega is a celestial princess called Tanabata. She falls in love with a mortal, Kengyu, represented by the star Altair. When Tanabata’s father finds out, he is enraged and forbids her to see this mere mortal. Thus the two lovers are placed in the sky, where they are separated by the Celestial River, known to us as Milky Way. Yet the sky gods are kind. Each year, on the seventh night of the seventh moon, a bridge of magpies forms across the Celestial River, and the two lovers are reunited. Sometimes Kengyu’s annual trip across the Celestial River is treacherous, though, and he doesn’t make it. In that case, Tanabata’s tears form raindrops that fall to earth.
Another triangle
To the right of the Vega (top star in the summer triangle) you may notice another triangle of bright “stars,” two of which are not stars at all, but planets. Saturn and Mars join Antares this weekend as they have been doing since April and will continue until late August, forming a tight-knit trio of brightness. But because the planets wander among the “fixed stars” this triangle is temporary, unlike the Summer Triangle that is a mainstay of Northern Hemisphere night skies every summer.
A Square
About 10:30 on Saturday night, the moon will rise, and accompanying it will be the Great Square of Pegasus to its left. This constellation will feature prominently in next week’s instructions on how to locate the Delta Aquarid meteor shower, which occurs late July to mid August.
Thank you for keeping up with the Night Sky articles. Comments and feedback are always welcome. If you are out later on in the week, each star rises about four minutes earlier each day than written here, and the moon rises 50 minutes later. Night Sky is researched and compiled by Lisa Davis-Burnett. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
