Messier 74 (also known as NGC 628 and Phantom Galaxy) is a large spiral galaxy in the constellation Pisces. It is about 32 million light-years away from Earth. The galaxy contains two clearly defined spiral arms and is therefore used as an archetypal example of a grand design spiral galaxy. Its relatively large angular size and the galaxy’s face-on orientation make it an ideal object for professional astronomers who want to study spiral arm structure and spiral density waves. It is estimated that M74 hosts about 100 billion stars.
M74 is the brightest member of the M74 Group, a group of 5 to 7 galaxies that also includes the spiral galaxy NGC 660 and a few irregular galaxies. Three supernovae have been observed in M74. In 2005 the Chandra X-ray Observatory announced its observation of an ultraluminous X-ray source (ULX) in M74, radiating more X-ray power than a neutron star, in periodic intervals of around two hours. It has an estimated mass of 10000 M☉. This is an indicator of an intermediate-mass black hole.
