One sky, three traditions: a guide for teachers

日本語

The stars are the same for everyone, but the pictures people made of them are not. This guide takes five patterns that are easy to find and shows how three traditions joined and named the same stars: the 88 constellations of the International Astronomical Union (the Western sky), the traditional Japanese names, and the traditional Chinese sky of the Three Enclosures and the Twenty-Eight Mansions. Each pattern links to the demo with that tradition chosen and the figure picked, so a class can switch between the three and watch the lines change on the same stars.

Everything here is what hoshi-stars holds: its stars, its names and readings, and its figures. The short stories are told in our own words. The limits of what it holds are at the end; please read them before you teach from it.

How to use the demo in class

• Open a link below. The figure is picked and its card shows its names, its reading and what it is.
• Switch Sky culture between Western, Japanese and Chinese: the same stars stay where they are, and only the lines and names change.
• Ask: which stars did each tradition choose? Which stars are left out? What did each people see in them?

1. Orion, 鼓星 and 參宿

In the West, Orion is a hunter with a belt of three stars. In Japan the same stars make a tsuzumi, a hand drum that is narrow in the middle: the belt is the drum's waist. Japan also named the two brightest stars apart: red Betelgeuse is 平家星 (へいけぼし, Heike-boshi) and white Rigel is 源氏星 (げんじぼし, Genji-boshi), after the red and white banners of the two clans of the Genpei war, and the belt is 三つ星 (みつぼし, Mitsuboshi), "three stars". In China the figure is 參, "three", for the same three belt stars, and it is one of the seven mansions of the White Tiger in the west of the sky.

Western · Japanese · Chinese

2. The Big Dipper, 北斗七星 and 北斗

The seven stars are not a constellation in the West: they are part of the Great Bear, and the Big Dipper is an asterism, a pattern inside a constellation. The line through the two stars at the front of the bowl points to Polaris, the pole star. Japan took the Chinese name, 北斗七星, and also calls them 七つ星 (ななつぼし, "seven stars") and 四三の星 (しそうのほし, "the four-and-three stars", four in the bowl and three in the handle). In China the dipper is a ladle near the pole, and an old saying reads the seasons from where its handle points in the evening.

Western · Japanese · Chinese

3. The Pleiades, 昴 and 昴宿

A small, tight group of stars that most eyes see as six or seven. The West calls them the Seven Sisters, a cluster in Taurus and number 45 of Messier's list. Japan calls them 昴, Subaru, and 六連星, "six stars in a row". In China they are 昴, one of the seven mansions of the White Tiger, like 參 of the first pattern.

Western · Japanese · Chinese

4. The Summer Triangle, 織姫 and 彦星, 織女 and 河鼓

The West joins three bright stars of three constellations, Lyra, Aquila and Cygnus, into one triangle for summer evenings. Japan and China tell a story about two of them instead. Vega is a weaver, the daughter of the Emperor of Heaven, and Altair a herdsman; once they married they neglected their work, and her angry father set them on either side of the Milky Way, the river of heaven (天の川, あまのがわ, Amanogawa). Once a year, on the seventh night of the seventh month (of the old lunar calendar in China, and in Japan before it took up the Western one), they may meet: the festival is Tanabata (七夕) in Japan and Qīxī (七夕) in China. In the Chinese sky the weaver's figure is 織女, Vega and the small stars beside it, and Altair is the brightest star of 河鼓, the River Drum. Deneb has no part in the story.

Western · Japanese · Chinese

5. Scorpius and the Heart of the Azure Dragon

The West sees a scorpion, with red Antares at its heart. China sees part of a much bigger animal: the Azure Dragon of the east, whose seven mansions run across this part of the sky. Antares is the middle star of 心, the Heart, and the scorpion's long tail is the dragon's 尾, the Tail. Orion and Scorpius lie on opposite sides of the sky, so one sets as the other rises; an old Chinese saying uses 參 (Orion's belt) and 商 (an old name of the Heart) for two people who never meet. Japan has old folk names for these stars too, but hoshi-stars does not hold them yet, so its Japanese sky shows the constellation under its modern name.

Western · Japanese · Chinese

Three limits to tell your class

• The Chinese lines are our own joins. The sources say which stars carry each Chinese name, not how the old star maps joined them. The lines in the demo are drawn by this package, and an old map may join the same stars another way.
• Some stars are not in our data. The package holds the stars to magnitude 6.0, about as faint as an eye can just see on a dark night. Many Chinese figures have fainter stars, and our source (Wikidata) does not give every bright one a catalogue number, so some stars of a figure are not drawn; a figure's card says when it lacks some (參, 昴, 織女 and 河鼓 each lack at least one), as "not in our data", since we cannot always tell which reason it is.
• The Chinese names come from Wikidata. Which star carries which Chinese name was read from Wikidata, a database anyone may edit, and has not been checked star by star against the old catalogues. The Japanese names come from one published list of traditional names. Treat both as a good start, not the last word.

The names, readings and figures of the three skies, and where each came from, are in Sky cultures and Data and licences.