Although technically located in the constellation of Coma Berenices, Galaxies M98, M99, and M100 are part of the Virgo Galaxy Cluster, a collection of more than a thousand galaxies that forms the heart of the Local Supercluster of galaxies. It is sometimes also called the Virgo-Coma Cluster. Hold your mouse cursor over the image to see the identifications of the brighter galaxies in the image. Galaxies with only a number next to them are NGC objects.

Galaxy M100, at upper left, is a grand-design SBbc spiral galaxy. It is also one of the brightest galaxies in the Virgo Cluster at a visual magnitude of 9.3. It has an apparent size of 7.5 x 6.1 arcminutes. It lies at a distance of 50 million light-years and contains more than 100 billion stars. The Hubble Space Telescope's study of Cepheid variable stars in M100 led to the first reliable distance measurement of a galaxy in the Virgo Cluster.

Galaxy M99, at bottom center, is a 9.7 magnitude Sc spiral galaxy with an apparent size of 5.3 x 4.6 arcminutes. It is called "Saint Katherine's Wheel" and the Coma or Virgo Cluster "Pinwheel."

Galaxy M98, at right, is a magnitude 10.1 SBb spiral with an apparent size of 9.8 x 2.8 arcminutes.

Pierre Méchain discovered M100 and M99 on March 15, 1781, and then M98 on March 17 of the same year.

The brightest star in the image, at lower right, is 6 Coma Berenices, a 5th magnitude star.

North is to the top in the above image.

M98, M99, M100 Catalogs: M98: NGC 4192 M99: NGC 4254 M100: NGC 4321 Common Name: M99: St. Katherine's Wheel Object Type: M98: SAB(s)ab Galaxy M99: SA(s)c Galaxy M100: SAB(s)bc Galaxy Magnitude: M98: 10.1v M99: 9.7v M100: 9.3v Size: M98: 9.8' x 2.8' M99: 5.3' x 4.6' M100: 7.5' x 6.1' Constellation: Coma Berenices Image Field Centered At: RA: 12h 18m 31s Dec: +15° 10' 18" Individual galaxy coordinates for the Messier galaxies in this image can be found in the Master List.