This stunning image shows the well-defined arms of the grand design spiral galaxy Messier 99.
Messier 99 resides approximately 42 million light-years away in the constellation of Coma Berenices.
This galaxy has an unusual, asymmetric shape with a displaced core and unequal spiral arms. It is a rare example of a galaxy with one dominant spiral arm.
Also known as M99, the Coma Pinwheel, NGC 4254, IRAS 12162+1441 and LEDA 39578, it has a diameter of around 80,000 light-years.
It contains about 100,000 million solar masses and belongs to the Virgo Cluster, a concentration of several hundred galaxies.
Messier 99 was discovered, together with the neighboring Messier 98 and Messier 100, by the French astronomer Pierre Méchain on March 15, 1781.
Charles Messier observed it a month later and saw a ‘nebula without star, of a very rare light, but a little clearer than the previous. The nebula is between two stars of the 7th & 8th magnitude.’
“Messier 99 is called a grand design spiral galaxy because of its distinctive pinwheel shape with prominent arms,” ESO astronomers said.
“Since Charles Messier first observed it in the 18th century, modern technology has allowed us to observe galaxies like this in significantly greater detail.”
This image of Messier 99 is a composite of data taken with ESO’s Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA).
“The VLT data, shown in blue and purple tones, was captured with the Multi-Unit Spectroscopic Explorer (MUSE) instrument, mapping the distribution of stars,” the researchers said.
“The ALMA data — shown here by the red and orange regions — originates from cold clouds of gas which can eventually collapse into stars.”
“Comparing these two datasets allows for a better understanding of how stars form.”
The image was taken as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) survey, which produces high-resolution images of nearby galaxies across all wavelengths of light.
“This will allow astronomers to learn more about the diverse range of galactic environments found in our Universe,” the scientists said.
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