Happy Qixi (七夕) festival! As today is the seventh of July (七月初七 qīyuè chūqī) according to the Chinese lunar calendar, it’s a special day for single women and couples alike. Literally meaning “The Night of Sevens”, Qixi celebrates the love, loyalty and commitment between lovers, as well as every single lady’s right to wish for her own Prince Charming to enter her life.

In recent years, Qixi has become known as Chinese Valentine’s Day, but it is by no means the exact equivalent of the Western day of romance. Qixi was originally a celebration based on the night sky. If you can somehow avoid the urban light pollution and be lucky enough to find some clear skies tonight, you’ll be able to observe a sad and symbolic reunion of a couple cruelly separated by a broad and powerful river…As you may already have guessed, the couple are really just personifications of two stars that lie on either side of the Milky Way.

For observers in the northern hemisphere, face south and look up right above your head around 10 p.m local time. The Milky Way should appear as a glowing band scorching the sky from north to south. Look for a bright blue-white star to the west of and above the Milky Way—this is Zhinü Xing (织女星, the Weaving-girl Star), the estranged wife of the love story. Below the Milky Way to the east is her forlorn husband, Niulang Xing (牛郎星, the Herd-boy Star), or Qianniu Xing (牵牛星, [the boy] Holding Cattle Star).

Many will already be familiar with the lovers’ story, but here’s a quick recap: As a goddess, Zhinü falls in love with Niulang, a mortal farm boy. They swiftly get hitched and have two children on earth, but the Queen Mother of Heaven (王母娘娘 wángmǔ niángniang) is furious to discover this forbidden celestial–mortal love and separates them on either side of the aforementioned river.

Qixi is the only night of the year the couple is allowed to reunite—by crossing a bridge formed by magpies (鹊桥 quèqiáo). If you happen to see a meteor shoot across the Milky Way tonight, it is said to be a lantern held by one of the couple as they cross the bridge to meet the other. On Niulang Xing’s left and right are two slightly dimmer stars, representing the couple’s two children.

In modern astronomy, Zhinü Xing is known as Vega, the brightest star of the constellation Lyra. Being the second-brightest star of the entire northern celestial sphere, after Arcturus, Vega should be fairly easy to spot. Niulang Xing is known as Alpha Altair, the brightest star in the constellation Aquila. The supposed children of Niulang and Zhinü are Beta Altair and Gamma Altair. Together with Deneb, the brightest star in the constellation Cygnus, the three stars form the prominent “Summer Triangle.” Take a look at the picture and see if you can find the triangle for yourself. The truth about Zhinü and Niulang is nothing like the Qixi legend. The two stars are approximately 16.4 light years away from each other and show no signs of getting closer.

Now that you’ve found these stars, you may be interested (though perhaps unsurprised) to know that traditional Chinese astronomy operates under an entirely different system of stars and constellations than that recognized by the International Astronomical Union.

Astronomy was a serious business in ancient China. As long as 4,300 years ago, an astronomical officer was already regarded as an important position in a tribe. His duty was to “观象授时 (guānxiàng shòushí),” or observe and record the movements of celestial objects, and formulate a calendar to guide the daily lives of his people, especially their agricultural activities.

As early as the Shang Dynasty (2070 B.C. – 1600 B.C.), the sky was divided into 31 regions, each consisting of a group of stars. The Three Enclosures (三垣 sānyuán) formed the centerpiece of the northern night sky, and can be observed all year around. Ancient Chinese thought of them as the residence and work place of the Jade Emperor (玉帝 Yùdì) and his ministers, as well as the busy downtown streets they governed.

Surrounding these central three regions are the remaining 28 star clusters, known as the Twenty-Eight Mansions (二十八宿 èrshíbā xiù), which can only be observed at certain times of the year. They were further divided into four groups of seven, one for each of the four cardinal directions. Four mythological creatures were assigned to represent these four regions: the Azure Dragon (青龙 qīnglóng) for the East, the Vermillion Bird (朱雀 zhūquè) in the South, the White Tiger (白虎 báihǔ) in the West and the Black Tortoise (玄武 xuánwǔ) for the North. Collectively, they are known as the Four Symbols (四相 sìxiāng), and were used by ancient Chinese to represent the four main points of the compass.

Besides the folk story, Niulang Xing and Zhinü Xing are important stars in officials record, too. Both belong to the region of the Black Tortoise, though they appeared under different names. According to the star chart reference book 《仪象考成》 (yíxiàng kǎochéng ), revised in 1752 under royal command, Niulang Xing is also called Hegu Er (河鼓二, the second star of the river drum). Together with the two nearby stars, they were thought to be the drums used by the heavenly troops as they rested by a river. Zhinü Xing is officially known as Zhinü Yi (织女一, Weaving-girl one).

There are lots of traditional ways to celebrate Qixi, but tonight, you can take your other half star-gazing and impress them with your knowledge of the legend and Chinese astronomy as a whole!