Two naked eye flaring Geosynchronous sats
After an alert on Dutch and Belgian astronomy mailing lists, several observers noted it as well.
I took images last night (22 May, 22:13 - 22:25 UTC) in hopes of catching it and identifying it from the position. I used the Canon 450D with the EF 50/2.5 Macro for that purpose.
Unfortunately, as it later turned out, "the" mystery geosat (for now) was hidden just behind some tree branches for me. A few degrees west of it, I however captured a second flaring geosat!
That one has now been identified by Bram and me, based on my photographic positions, as Milstar 5 (2001-001A, #27168). I have made a movie out of 13 images (10 second exposures) spaced one minute each. It can be seen here (1.4 Mb animated GIF)
The FOV of the movie is a small crop from the images, at full pixel level. The object is moving southwards at about 55"/minute.