This collection of galaxies
is an interacting group located in the Serpens constellation
named after the astronomer
Carl Seyfert who discovered the group in the 1940's. Also known as NGC 6027 or Hickson 79, if you prefer random configurations of letters and numbers. This assemblage
is one of the densest compact group
s, occupying less volume than our Milky Way
. The cluster
spans 100,000 light year
s and each of the participating galaxies is roughly the same size, about 35,000 light years across.
The name of the group is slightly misleading, the set of interacting galaxies has cardinality of four, not six. One of the proported galaxies is actually a tidal tail of stars that have been torn from one of the other galaxies. (I am enjoying the cognitive dissonance that arises as I see the word "tidal" applied to vast assemblages of stars...) The other, a beautifully defined spiral galaxy that we view straight down the axis of, as indicated by its discordant red shift, is actually five times farther away than the 190 million light years that seperate our system from the four truly interacting galaxies. It's appearance as part of the group seems to be beautiful, if unlikely, chance.
A notable difference between Seyfert's sextet and other groups of interacting galaxies like it is that this configuration is curiously devoid of the clusters of newly created stars that usually mark collisions between galaxies. This absence suggests that these galaxies have just begun to interact with each other. As the interactions proceed, the gravitational forces will cause the bodies to tear at each other, destroying that which was there previously while at the same time becoming a nursery to new stars. After a few billion years, the gravitational pulls will reach equilibrium, and the four could merge into one complete mega-galaxy. Achingly slow destruction/creation.
For a limited time only: check my homenode for the Hubble image. The tidal tail of stars is the right-most object, while the clearly-defined spiral galaxy near the center is the odd man hundreds of millions of miles out.