Huagai (華蓋)

Huá Gài (Canopy of the Emperor, 華蓋) is a Chinese asterism consisting of sixteen stars, divided into two parts: seven stars forming the Huá Gài (“Canopy”) proper and nine forming the Gàng (“Shaft”). The configuration of this asterism varied considerably over time. In its earliest form, it was located within the modern constellation Cepheus, but later versions shifted its position toward Cassiopeia and Camelopardalis. The asterism originated within the Gan school during the Han dynasty, around the first century BCE.

Concordance, Etymology, History

The term Huá Gài originally denoted an ornate ceremonial canopy used in the carriages and processional retinues of ancient emperors. Those used by ministers were called simply gài (“canopy”) or sǎn (“umbrella”). Although the canopies differed in form and structure, they could be generally classified into two types according to the shape of their handle: the “straight canopy” (zhí gài) and the “curved canopy” (qū gài).

• Ancient Canopies
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  Curved-Handle Feathered Canopy(Left Top) in the Xiwangmu Banquet Mural, Late Eastern Han, Mandong Township, Jiaxiang County, Shandong Province

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  Canopy Depiction on the West Wall of the Xiao Stone Shrine, Songshan, Mandong Township, Jiaxiang County, Shandong, Eastern Han Dynasty

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  Processional Scene of Emperor Hui of Han under Parasol and Fan on Lacquer Tray, Excavated from Nanchang Railway Station M3 Tomb, Dated to the 8th Year of Yonghe(352 CE)

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  Canopy in Image of Master Tan Yan Praying for Rain on the South Wall of Mogao Cave 323 Early Tang Image

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  Depiction of Canopy in Differet Style by MIBEN(觅本)

According to the Gu jin zhu (Notes on the Past and Present, 古今注) compiled by Cui Bao (fl. Western Jin, 3rd–4th century CE), the curved canopy was invented by the Western Zhou (西周， strategist Jiang Taigong (姜太公， ？- 1015？ BCE):

“The curved canopy was made by Taigong. When King Wu（武王， 1076 - 1043 BCE） campaigned against King Zhou(紂王， ？- 1046？ BCE) of Shang Dynasty, a strong wind broke his canopy; Taigong, inspired by the broken shape, designed the curved canopy.”

However, this account is likely legendary, as no archaeological evidence of a carriage canopy with a curved handle has yet been found.

Carriage canopies were generally straight-handled, while those used in ceremonial processions often had curved handles—likely to allow the attendant holding the canopy to stand slightly apart from the dignitary beneath it. Numerous Han to Tang dynasty murals depict emperors or celestial beings sheltered under a curved canopy. The earliest configuration of the Huagai asterism appears to mirror precisely this type of canopy structure.

Identification of stars

Constellation	Star Names or Orders(Qing)	Yi Shitong Based on catalogue in 18th century	Pan Nai based on Xinyixiangfayao Star Map	SUN X. & J. Kistemaker Han Dynasty	Boshun Yang before Tang dynasty	Boshun Yang Song Jingyou(1034)	Boshun Yang Song Huangyou(1052)
Huagai	1st(Determinative)		iota Cas	omega Cas	16 Cep	omega Cas	iota Cas
	2nd	40 Cas	40 Cas	49 Cas	gamma Cep	31 Cas	RZ Cas
	3rd	HIP 5926	42 Cas	40 Cas	pi Cep	psi Cas	SU Cas
	4th	31 Cas	omega Cas	42 Cas	31 Cep	43 Cas	HIP 12821
	5th	psi Cas	HIP 12821	HIP 12821	24 Cep	iota Cas	omega Cas
	6th	43 Cas	SU Cas	SU Cas	11 Cep	HIP 12821	42 Cas
	7th	omega Cas	A Cas	A Cas	betta Cep	SU Cas	A Cas
Gang	1st(Determinative)	gamma Cam	49H Cep 48(HIP 19461)	50 Cas	HIP 5928	HIP 25110	HIP 19461
	2nd	HIP 14862	HIP 14844	HIP 12273	HIP 115746	HIP 23265	HIP 14844
	3rd	49 Cas	46H Cep 30 (HIP 13055)	HIP 14862	HIP 109693	HIP 20776	HIP 13055
	4th	51 Cas	HIP 9568	HIP 15547	HIP 112833	HIP 19461	HIP 9568
	5th	50 Cas	47 Cas	HIP 14417	HIP 113116	HIP 14417	47 Cas
	6th	54 Cas	49 Cas	HIP 19461	HIP 112519	50 Cas	49 Cas
	7th	A Cas	HIP 10350	HIP 20776	rho Cep	A Cas	HIP 10350
	8th	42 Cas	50 Cas	HIP 23265	HIP 111242	42 Cas	HIP 12273
	9th	38 cas		HIP 25100	HIP 111660	38 Cas	50 Cas

Maps (Gallery)

Several ancient star maps preserve depictions of Huagai. The earliest known image appears in the Cheonsang Yeolcha Bunyajido (Charts for Celestial Branches and Field Allocations, 天象列次分野之圖). In this version, Huagai is positioned within Cepheus, differing from all later maps produced after the Tang dynasty. In this early chart, the asterisms Wǔ Dì zuò (“Seats of the Five Emperors”, 五帝內座) and Liù Jiǎ (“Six Jia”, 六甲) are shown directly beneath Huagai, precisely matching the description in the Gān’s Star Canon (Gān shi xing jing, 甘氏星經). Later maps, however, no longer conform to the textual record.

A record of a meteor observed in 512 CE reports that it passed through the region of Huagai; its trajectory corresponds only to the position shown on this early chart, while the locations drawn on post-Tang star maps do not align. In fact, Huagai was not the only asterism changed—other constellations near the northern gate of the Purple Palace (Zǐgōng, 紫宮) also shifted their position due to the apparent northern expansion of the wall in later charting traditions.

The most striking comparison lies in morphology: only the Huagai depicted on this earliest star map preserves the authentic early form of a curved-handled imperial canopy and its shaft (gàng). In contrast, later depictions from the Tang dynasty onward exhibit noticeably distorted shapes, reflecting a departure from the original symbolic design.

historical map	modern identification (Yang 2023)	same in Stellarium 25.3
Huagai and Gang on Cheonsang Yeolcha Bunyajido	Huagai and Gang before Tang Dynasty Reconstructed by Boshun Yang (2023)	Huagai, Gang and a few neighbouring asterisms before Tang Dynasty in Stellarium
Huagai and Gang on Dunhuang Star Map	Huagai and Gang in Early Song Dynasty (1034CE) Reconstructed by Boshun Yang (2023)	Huagai, Gang and a few neighbouring asterisms in 1034 in Stellarium
Huagai and Gang on Geziyuejintu
Huagai and Gang on Suzhou Star Map	Huagai and Gang in Huangyou Era in Song Dynasty (1052CE) Reconstructed by Boshun Yang (2023)	Huagai, Gang and a few neighbouring asterisms in 1052 in Stellarium
Huagai and Gang in 18th Century Star Map	Huagai and Gang in 18th Century Reconstructed by YI Shitong (1981)	Huagai, Gang and a few neighbouring asterisms in 18th Century in Stellarium

Star Name Discussion (IAU)

In 202x, the name of the historical constellation "xxx" was suggested to be used for one of the stars in this constellation. ...

Decision: ...

References

References (Chinese)