[BAA Comets] Alcock's possible prediscovery of C/Pererya

[David Seargent]

Dear all,
 
I read that G. E. D. Alcock saw a pencil-thin beam of light in the morning twilight in September 1963, just a few days before the sungrazing Comet Pererya was discovered. It seems very likely that what he saw was the tail of the comet, but does anyone have more information about this? Was the "beam" seen naked eye or through binoculars?
Any information would be greatly appreciated.
Cheers,
David Seargent