Cartwheel Galaxy

Common card · No. 342816

The Cartwheel Galaxy (catalogue ESO 350-40 and PGC 2248) is a lenticular ring galaxy around 500 million light-years away in the constellation Sculptor. It has a D25 isophotal diameter of 57.69 kiloparsecs (188,200 light-years), and a mass of about 2.9–4.8 billion solar masses; its outer ring has a circular velocity of 217 km/s. It was discovered by Fritz Zwicky in 1941. Zwicky considered his discovery "one of the most complicated structures awaiting its explanation on the basis of stellar dynamics." The Third Reference Catalogue of Bright Galaxies (RC3) measured a D25 isophotal diameter for the Cartwheel Galaxy at about 60.9 arcseconds, giving it a diameter of 57.69 kiloparsecs (188,200 light-years) based on a redshift-derived distance of 132.2 megaparsecs (431 million light-years). This diameter is slightly larger than that of the Andromeda Galaxy. The large Cartwheel Galaxy is the dominant member of the Cartwheel Galaxy group, consisting of four physically associated spiral galaxies...

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