Simply 2° northeast of Sixth-magnitude 6 Comae Berenices is Ninth-magnitude M100. Situated some 55 million light-years distant, it’s the Virgo Cluster’s brightest spiral galaxy. The galaxy was one other discover in 1781 by French comet hunter Pierre Méchain, who notified his comet companion Charles Messier. Like M98 and M99, Messier discovered it tough to detect, potential “solely below nice circumstances, and close to meridian passage.”
One can solely think about their response had they lived in the present day to see this face-on spiral galaxy — comprised of some 400 billion suns unfold throughout 100,000 light-years of space — in all its glory. M100 is a grand-design spiral and, like M51, shows two distinguished, well-defined spiral arms (and a number of other fainter ones) that uncoil from the ends of a central bar like a whirligig.
Infrared photographs present the galaxy’s arms sweeping out from a distinguished ring of scorching, shiny dust (an space of intense star formation) that surrounds the interior galactic core. Episodes of starburst exercise have been occurring on this ring for the previous 500 million years. The arms present a slight asymmetry (being brighter towards the south) and regularly turn out to be cooler as they recede from the core.
M100 is a difficult object to watch via a small telescope, primarily as a result of its mild is unfold throughout 6′ of sky — virtually twice the extent of the Owl Nebula, which is a full magnitude brighter! Even utilizing excessive magnification, search for a pale orb with a comfortable core and no central starlike nucleus. Spend a while behind the eyepiece, although, and sweep your eye throughout the galaxy’s face to see in case you can decide up hints of spiral enhancement. Supernova hunters needs to be conscious that M100 has produced seven supernovae between 1901 and 2020.
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