ISOHDFS 27

ISOHDFS 27 is a spiral galaxy in the constellation Tucana, and was discovered in the Hubble Deep Field South survey. It is the most massive spiral galaxy found in the survey, measuring 130000 ly in diameter. It is located approximately 6 e9ly from Earth and has a mass greater than 1000 billion times the mass of the Sun, making it about four times as massive as the Milky Way.

It was once thought to be the largest spiral galaxy in the universe, but it has since been dethroned by NGC 6872.