Zhúlóng (galaxy)

Zhúlóng is an extremely massive grand-design spiral galaxy located at a redshift distance of z=5.2 (12.8 Gly) in the constellation of Sextans. It is believed to be the most distant known grand design spiral galaxy. Spiral galaxies beyond red shift 3.0 are generally rare with only a few known.^[2]

Zhúlóng
Zhúlóng imaged by the James Webb Space Telescope
Observation data (J2000 epoch)
Constellation	Sextans
Right ascension	10h 00m 29.97s[1]
Declination	+02° 05′ 34.51″[1]
Redshift	5.2[1]
Distance	3.9 Gpc (12.8 Gly)[1] (Light travel distance)
Characteristics
Type	Sbc
Size	~62,000 ly (19 kpc) (estimated)[1]
Apparent size (V)	3″ × 3″[1]
Notable features	Most distant known grand design spiral galaxy

The galaxy has well-defined spiral arms that have dense star formation regions while the core is quiescent. However the rate of star formation is low forming 66 solar masses of stars per year. The size of this galaxy is comparable to the Milky Way galaxy, being an estimated 62,000 light years in diameter.^[2] It has a mass of around 100 billion solar masses.^[3]

Naming

The galaxy was named Zhúlóng meaning “Torch Dragon” in Chinese mythology. In the myth, Zhúlóng is a powerful red solar dragon that creates day and night by opening and closing its eyes, symbolizing light and cosmic time.^[4]

Discovery

Zhúlóng was discovered by a team led by Mengyuan Xiao, and announced in a paper submitted to Astronomy & Astrophysics on 17 December 2024, and published on 16 April 2025.^[1] The discovery was surprising to astronomers, who had previously believed that spiral galaxies took billions of years to develop.^[4]

Image gallery

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  PANORAMIC Survey showing position of Zhúlóng, imaged by the James Webb Space Telescope