Less than a year after the 42nd known Mersenne prime was reported
(MathWorld headline news, February 26, 2005), the GIMPS project has
discovered the 43rd known Mersenne prime: 2^30402457 - 1. The discovery was
made by Drs. Curtis Cooper and Steven Boone, professors at Central Missouri
State University on December 15, tentatively announced by GIMPS organizer
George Woltman on December 19, and independently verified by Tony Reix on
December 25. The new Mersenne prime has 9,152,052 decimal digits, making
it not only the largest Mersenne prime known, but also the largest known
prime of any type.

Less than a year after the 42nd known Mersenne prime was reported (MathWorld
headline news, February 26, 2005), GIMPS project organizer George Woltman is
reporting in an email message that a new Mersenne prime has been reported to
the GIMPS server. A verification run on the number has been started, and will
take a week or two to complete. The potential prime was identified by an
experienced GIMPS participant and no errors were reported during the run, so
it seems likely that a new Mersenne prime has indeed been found. While the
exponent of the potential prime has not yet been revealed, it has has fewer
than ten million digits.