Below is Joel's note announcing the find of the new prime M1398269. (I shortened the header and made his URL's live.)
Date: 23 Nov 96 12:04:41 EST
From: "George F. Woltman" <74473.2626@CompuServe.COM>
To: ..
Subject: New Mersenne Prime!

The Mersenne Newsletter, issue #8 November 23, 1996

New Mersenne Prime! 2^1398269-1 is prime!

Thanks to everyone's hard work, GIMPS (Great Internet Mersenne Prime Search) has discovered the 35th known Mersenne Prime! Joel Armengaud made the discovery on November 13. Amazingly, he kept this secret while he double-checked the find on two other computers. On the 18th, he notified Richard Crandall, Chris Caldwell, and myself. I verified it on my machine on the 20th. Slowinski, who was out of town at the time, provided the independent verification on the 22nd.

More information can be found at these three web sites:

As had been agreed upon before hand, credit for this new prime will go to Armengaud, Woltman, et al.

We were incredibly lucky to find this prime. In percentage terms, this is the 6th smallest gap between Mersenne exponents. The range from 1,000,000 to 2,000,000 was expected to contain 1.78 Mersenne primes. There are already 2 known and probablities suggest there will be one more. Let's go find that one too!

Congratulations to all,
George Woltman