Details: M98 was discovered in 1781 by French astronomer, Pierre Mechain, who was a friend and compatriot to Charles Messier, the one actually credited with cataloging it. M98 is somewhat atypical in that instead of the typical redshift that most galaxies exhibit indicating they travel away from us, M98 has a blueshift indicating it travels toward us at 140 km/s. But no worries, even if M98 were aimed straight at us, it would take nearly a trillion years, or about 8 times the age of our universe, to reach and collide with our own Milky Way Galaxy. M98 has a galaxy morphological classification of SAB(s)ab. The SAB denotes an intermediate spiral galaxy, the ab denotes it has a intermediate to tightly wound spiral arms beginning at a well-defined central bulge, and the (s) indicates no detectable inner ring to the galaxy.

Inclined and Active: M98 contains 100s of billions up to a trillion stars, and is so far away that they resolve into individual stars only using the largest ground or space based telescopes such as this 1995 Hubble Wide Field Camera image. These stars organize into a very circular spiral disk, however, that disk has a highly inclined angle toward us along our line of site, so it appears highly elliptical instead of its actual circular shape. Its overall mass is about 80 billion times the mass of our sun and with the equivalent of an additional 85 billion solar masses of interstellar dust. Its nucleus is an active one indicating it is compact, emits an enormous amount of energy not associated with stars, and thereby typical of what is theorized to be an active supermassive black hole. The red regions visible from the center nucleus and throughout the inner spiral arms are HII regions, or ionized molecular hydrogen, meaning that active star formation is and has been taking place.

Clusters and Superclusters: M98 is a member of the Virgo Cluster which is a large cluster of galaxies centered at over 50 million light-years away in the direction of the constellation Virgo, the maiden. This Virgo Cluster contains between 1300 and 2000 individual galaxies, each with a 100 billion to over a trillion stars! It is so large it covers parts of both the constellation Virgo and Coma Berenices. The Virgo Cluster is part of the Virgo Supercluster, a supercluster of galaxies containing multiple clusters including the Local Group, of which our own Milky Way Galaxy is a part. It is theorized that M98 interacted with M99 three quarters of a billion years ago, although they are now about 1.3 million light-years apart.

Abell Galaxy Cluster: Just to the right and below M98, visually, is a portion of the Abell Cluster 1499 which is a large and rich cluster of galaxies at about 2 billion light-years away. It contains somewhere between 100 and 1000 galaxies, some visible here, including a quasar, just off the right edge of this image and therefore not visible. Quasars are thought to be the very active cores of early galaxies where the early formation of supermassive black holes releases immense amounts of energy including visible light.

Annotations. In the image above, hover a mouse or curser over the image to show annotations of Messier 98, with several enlarged insets identifying interesting features! Starting at the left of the image, is a bright orange-red star, meaning low temperature compared to white or blue stars. Bottom left shows two stars that are actually gravitationally bound together as a binary star system. Over half of all stars are part of a binary system, but most are too far away and appear as only single stars. Center of the image are enlarged insets of the galaxy nucleus as well as the red HII regions indicating star formation in the inner spiral arms.

In the lower right corner of the image is the Abell Galaxy Cluster 1499 containing over 100 distant galaxies, several of which are enlarged and inset. In the upper right are galaxies PGC 39002 and NGC 4186, neither are part of the Abell 1499 cluster, nor associated with M98. Both are 100-500 million light years way, but unknown if they are gravitationally close to each other.

Below Images: The image below is the same image as above but processed to remove all stars. Since most of the stars in the image are in our own galaxy, this is what the galaxy would appear like outside of our galaxy, if no stars existed along our line of sight. Using a mouse to hover over the image brings all the stars back. The second image below is a zoomed in version of M98. Hovering a mouse over this image makes the stars disappear. Finally, the last image below is a comparison with the current generation of processing to my old generation 2 processing. This is the same data, same set of preprocessed images, but with improved processing techniques. Hovering the mouse over the image fades from the old image to the new processing!

Object Statistics: Constellation: Coma Berenices, Right Ascension: 12h 13m 48s, Declination: +14° 54' 1.7”, Apparent Magnitude: 10.1, Size: 9’.8 x 2’.8 (126,000 to 160,000 light-years diameter), Distance 44-60 million light-years.