P Cygni | Article about P Cygni by The Free Dictionary
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P Cygni (sig -nÿ, -nee) A massive luminous blue variable about 2000 parsecs away in the constellation Cygnus. It has undergone random outbursts: in both 1600 and 1653 it brightened considerably then faded, but since 1700 its brightness has very gradually increased. It is also an ultraviolet source that is gradually cooling, the UV brightness decreasing as the visual brightness increases. See also P Cygni stars.