There is a big disparity between the magnitude estimates listed in ISS Finder on my smartphone, which scrapes the date from Heavens Above, and what I find on CalSky. For tonight's event ISS Finder had it listed at mag -7.2 while CalSky said it would be mag -5.9. Either way it was plenty bright. I like using CalSky because it provides information that ISS Finder/Heavens Above does not provide, like the constellation the event will occur in, what surface(s) the flare will originate from and a starfield map so you know exactly where to look of the light pollution isn't too bad to obliterate any nearby stars.
Tonight I sat in Grace Plaza and was able to find Vega nearly oberheat in early twilight. As the sky darkened Deneb(mag 1.2), Sadr (mag 2.2), Gienah (mag 2.5) and δ Cyg (mag 2.8) became visible but I never did see Alberio (mag 3.0) for sure. It seemed to me that the satellite crossed the neck of the swan between η Cyg and Alberio rather than between Sadr and and η Cyg as the star chart indicates. The brightest part of the flare was probably when the satellite appeared to be between Alberio and the fletchings of Sagita, probably about even with the Coathanger.
CalSky graphic
