Astronomy: Cartwheel Galaxy

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Cartwheel Galaxy The Cartwheel Galaxy (catalogue ESO 350-40 and PGC 2248) is a lenticular ring galaxy about 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.

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Commentary

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Why Cartwheel Galaxy matters: Galaxies are the fundamental building blocks of the visible universe. Studying them reveals how matter organized itself after the Big Bang and continues to evolve billions of years later. It was discovered by Fritz Zw icky 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. The three companions are referred to in several studies as G1, the smaller irregular blue Magellanic spiral; G2, the yellow compact spiral with a tidal tail; and G3, a more distant spiral often seen in wide field images. One supernova has been observed in the Cartwheel Galaxy. SN 2021afdx (Type II, mag. 18.796) was discovered by ATLAS on 23 November 2021.

Commentary

Source: Internal

Deep dive: Cartwheel Galaxy 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 Cat alogue 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. The three companions are referred to in several studies as G1, the smaller irregular blue Magellanic spiral; G2, the yellow compact spiral with a tidal tail; and G3, a more distant spiral often seen in wide field images. One supernova has been observed in the Cartwheel Galaxy. SN 2021afdx (Type II, mag. 18.796) was discovered by ATLAS on 23 November 2021. Source: https://en.wikipedia.org/wiki/Cartwheel_Galaxy (Wikipedia, CC BY-SA)