Starship Asterisk*

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NGC 4921: Galaxy at the Edge

Spiral galaxy NGC 4921 presently is estimated to be 320 million light years distant. This image, taken by the Hubble Space Telescope, is being used to identify key stellar distance markers known as Cepheid variable stars. The magnificent spiral NGC 4921 has been informally dubbed anemic because of its low rate of star formation and low surface brightness. Visible in the image are, from the center, a bright nucleus, a bright central bar, a prominent ring of dark dust, blue clusters of recently formed stars, several smaller companion galaxies, unrelated galaxies in the far distant universe, and unrelated stars in our Milky Way Galaxy.

Credit: NASA, ESA, K. Cook (LLNL)

<<In medicine, a *COMA* (from the Greek κῶμα koma, meaning deep sleep) is a profound state of unconsciousness. A COMAtose person cannot be awakened, fails to respond normally to pain or light, does not have sleep-wake cycles, and does not take voluntary actions. *COMA* may result from hypoxia in which the body as a whole (generalized hypoxia) or a region of the body (tissue hypoxia) is deprived of adequate oxygen supply. Hypoxia in which there is complete deprivation of oxygen supply is referred to as anoxia.>>

Bill Melater wrote:Is there something missing from the explanatory text?

Since NGC 4921 is a member of the Coma Cluster of Galaxies, refining its distance would also allow a better distance determination to one of the largest galaxy clusters. NGC 4921 has been informally dubbed anemic because of its low rate of star formation and low surface brightness.

Bill Melater wrote:Is there something missing from the explanatory text?

Since NGC 4921 is a member of the Coma Cluster of Galaxies, refining its distance would also allow a better distance determination to one of the largest NGC 4921 has been informally dubbed anemic because of its low rate of star formation and low surface brightness.