The spiral galaxy NGC 1566, sometimes known as the "Spanish Dancer Galaxy," is seen in this vivid and dynamic-looking photo. NGC 1566 is classified as an intermediate spiral galaxy or weakly-barred galaxy, indicating that it lacks a prominent bar-shaped structure in its nucleus. The galaxy's name comes from its spiral arms' striking and dramatic swirling patterns, which resemble the forms and hues of a dancing figure. NGC 1566 is a member of the Dorado galaxy group and is located in the constellation Dorado, around 60 million light-years from Earth.
Galaxy groups are collections of galaxies that are held together by gravity. Galaxy clusters may include hundreds of galaxies, whereas groups may contain few tens of galaxies. Groups are smaller and less massive than galaxy clusters. Nevertheless, the distinction between a galaxy group and a galactic cluster is not well defined. Sharpening the criteria has been suggested by several astronomers; one notion is that galaxy aggregations with less mass than 80 trillion Suns should be considered galaxy groupings.
Credit: ESA/Hubble & NASA, D. Calzetti and the LEGUS team, R. Chandar
