The summer sky: Summer Triangle, the Cowherd and the Weaver, Scorpius

Summer nights bring the best Milky Way of the year. Near the zenith three bright stars make the easy Summer Triangle, and two of them are the Cowherd and the Weaver of the Qixi legend. Turn to the low southern sky and a scorpion of bright stars lies beside the Milky Way; the red star at its heart is the "Great Fire" of the old books.

The sky over Taipei, July 15, 9 p.m.

Taipei, July 15, 9 p.m.. The maps show the sky as you look up: north at the top, east on the left; the center is the zenith and the rim is the horizon. Planets and the Moon are left out because they move from year to year; use the tool on this page to see a given night.

You can see the same sky at about 7 p.m. in mid-August and about 11 p.m. in mid-June. The sky runs about two hours earlier each month, so the positions below work in other months if you shift the time.

All worked examples on these pages are calculated for Taipei (25°N). Further north, northern stars ride higher and southern ones lower; the tool on this page will redraw the sky for London, New York, Vancouver, Sydney and other cities.

Use this table to find them

Positions from our sky engine (Taipei, no refraction). Elsewhere in Taiwan the difference is small; further north, southern stars sit a few degrees lower for every degree of latitude you gain.

The Cowherd and the Weaver: two stars across the Milky Way

In the Qixi (Chinese Valentine's Day) legend, the Cowherd is Altair (He Gu Er, in Aquila) and the Weaver is Vega (Zhi Nü Yi, in Lyra). They face each other across the Milky Way, about 34° apart. The two little stars beside Altair are said to be the Cowherd's two children, carried on a pole. Note that the 28 mansions' Niu (Ox) and Nü (Girl) are two other, very faint mansions, not the Cowherd and the Weaver.

"The Fire flows in the seventh month" is about a star, not the weather

In the Book of Songs ode "Seventh Month", the "Fire" is Antares, the Great Fire. The line means that at dusk in the seventh lunar month the Great Fire has passed the meridian and is sinking west, so the weather is about to cool. Today the phrase is often used to mean scorching heat, which is almost exactly backwards.

Shen and Shang never meet

Du Fu wrote that people who never meet are "like Shen and Shang": Shen is the winter mansion in Orion, Shang is the mansion Xin in Scorpius, and they are nearly half the sky apart, one rising as the other sets. Our engine checked every ten minutes of 2027 in Taipei: Betelgeuse and Antares are both above the horizon only 3.2% of the time, and then both are hugging the horizon. Take away daylight and twilight, and the time you could see both in a dark sky adds up to about 118 hours for the whole year, all of it right down at the horizon.

Three common misconceptions