The spring sky: from the Dipper to Arcturus and Spica
On spring evenings the Big Dipper is at its highest of the year, which makes it the best place to start. Follow the curve of its handle outward and you reach two bright stars in turn, orange Arcturus and white Spica: "arc to Arcturus, speed on to Spica".
The sky over Taipei, April 15, 9 p.m.
Taipei, April 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-May and about 11 p.m. in mid-March. 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
| Target | Chinese name | Western name | Position, Apr 15, 9 p.m. | How to recognize it |
|---|---|---|---|---|
| The Big Dipper | 天樞 Tian Shu | Dubhe, Ursa Major | north, about 53° up | High in the north, bowl opening downward: the starting point for the whole spring sky |
| First stop on the arc | 大角 Da Jiao (大角星) | Arcturus, Boötes | east, about 40° up | The first bright star along the handle's curve, orange, the fourth-brightest star in the night sky |
| Second stop on the arc | 角宿一 Jiao Xiu Yi | Spica, Virgo | southeast, about 36° up | The same distance again, a white bright star; the determinative star of the mansion Jiao, the Dragon's horn |
| Leo | 軒轅十四 Xuan Yuan Shi Si | Regulus, Leo | southwest, about 75° up | High in the southwest: a backward question mark (Xuanyuan in Chinese) forms the lion's head, with Regulus at its base |
| The Spring Triangle | 五帝座一 Wu Di Zuo Yi | Denebola, Leo | southeast, about 70° up | Denebola at Leo's tail forms a big triangle with Arcturus and Spica |
| Heart of Hydra | 星宿一 Xing Xiu Yi | Alphard, Hydra | southwest, about 52° up | A lonely orange star west of south with nothing bright around it: the mansion Xing of the Vermilion Bird |
| Corvus | 軫宿一 Zhen Xiu Yi | Gienah, Corvus | southeast, about 41° up | A small quadrilateral of four stars southwest of Spica: the mansion Zhen |
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.
Can you see the Southern Cross from Taiwan?
Yes, depending on where and when. Acrux, the Cross's brightest star (declination about −63°), reaches only about 4.8° at Kenting in the far south, and Gacrux about 10.8°; from Taipei it barely clears the horizon. The best chance is around midnight in April and May from a beach at the southern tip of the Hengchun Peninsula with a clear view due south and very transparent air. From the continental US or Europe it is out of reach.
The "corpse vapor" in the Ghost mansion
Cancer is faint, but at its center is a hazy patch visible to the naked eye: the Beehive Cluster (M44) in the West. In China it sits inside the mansion Gui (Ghost), and its old name was Jishiqi, "corpse vapor". Look between Leo and Gemini on spring evenings from a dark site.
Three common misconceptions
Arcturus and Spica belong to the same mansion.
Both Chinese names contain jiao, "horn", but Arcturus (Dajiao, "Great Horn") in Boötes is a separate asterism near the mansion Kang; only Spica (Jiao Xiu Yi) in Virgo is the determinative star of the mansion Jiao.
On spring evenings you can see the whole Azure Dragon.
Early on spring evenings only Jiao and Kang are rising in the east; Fang, Xin and Wei stand high only after midnight or on summer evenings.
The Leonid meteor shower is in spring.
Leo is best on spring evenings, but the Leonids peak in mid-November, and you have to wait until after midnight for Leo to rise.
Tonight's sky: what is overhead right now
Pick a date, a time and a place to draw the whole sky at that moment, with the Moon, the planets, the bright stars that are up, and the Chinese lunar mansion crossing the meridian due south. Switch between Western constellation lines and Chinese asterisms. Everything is calculated in your browser.
Star catalog: about 1,600 Hipparcos stars brighter than magnitude 5 (compiled from d3-celestial, BSD license). The Moon and planets use simplified formulas accurate to within 0.3°; atmospheric refraction is ignored.
A straight word: this is astronomy, not fortune-telling
These pages are about stars you can actually see: where they are, which season brings them, and what East and West call them. The "mansion of the day" in the Chinese almanac, the twelve signs of Western astrology and the stars of Zi Wei Dou Shu all borrow star names, but they are separate systems of calculation and do not match what is in the sky that night. Everything on this site is for reference and entertainment.
Try another date: the sky on your night
Pick a date, time and place; the tool draws the whole sky with the Moon and planets marked.
The Spring Sky FAQ
What is the arc to Arcturus?
Follow the curve of the Big Dipper's handle outward to Arcturus in Boötes, then keep going to Spica in Virgo ("arc to Arcturus, speed on to Spica").
Which three stars make the Spring Triangle?
Arcturus in Boötes, Spica in Virgo and Denebola in Leo.
Can you see the Southern Cross from Taiwan?
From southern Taiwan, such as Kenting, around midnight in April and May, but very low: Acrux reaches only about 4.8°, so you need an unobstructed view to the south.