This image of the spiral galaxy NGC 4254, also known as the Coma Pinwheel or Messier 99, is a composite of data taken with ESO’s Very Large Telescope (VLT) and the Atacama Large/Submillimeter Array (ALMA). Credit: ESO/PHANGS This stunning image clearly shows the well-defined arms of the spiral galaxy NGC 4254, also known as the Coma Pinwheel or Messier 99. Because of its characteristic pinwheel shape with protruding arms, it is called a large-design spiral galaxy. It was discovered on March 17, 1781 by the French astronomer Pierre Méchain. He reported this to fellow French astronomer Charles Messier, who included the object in the Messier Catalog of comet-like objects. Modern technology has allowed us to observe galaxies like this in significantly greater detail compared to the first observation by Méchain and Messier in the 18th century. NGC 4254 is a large spiral galaxy in the northern constellation Berenice, about 49,000,000 light-years from our Milky Way. In Latin, Coma Berenices means “Hair of Berenice” and refers to Queen Berenice II of Egypt, who sacrificed her long hair as a religious offering. This image is a composite of data taken with ESO’s Very Large Telescope (VLT) and ESO’s co-owned Atacama Large Millimeter/Submillimeter Array (ALMA). The VLT data, shown in blue and purple tones, were recorded with the Multi-Unit Spectroscopic Explorer (MUSE) instrument, mapping the distribution of stars. The ALMA data – shown here by the red and orange regions – come from cold clouds of gas that may eventually collapse into stars. Comparing these two data sets allows for a better understanding of how stars form. This image was taken as part of the Physics in High Angular Rezult in Nearby GalaxieS (PHANGS) survey, which produces high-resolution images of nearby galaxies at all wavelengths of light. This will allow astronomers to learn more about the diverse range of galactic environments found in our Universe.
