As we approach this year’s Perseid maximum I had a look at the NEMETODE multi-year dataset to see what it could tell us about the shower’s peak activity profile.
The attached plot was derived from 8,199 observations of Perseid meteors recorded by 2 or more of our video stations. The data were corrected for radiant altitude, collated into bins of 0.2 degrees solar longitude (~4.8 hours bins) and derived a mean meteor count per camera.
The IMO describe the Perseids as displaying a broad maximum from sol. long, 139.8 deg. to 140.3 deg. (2020 Aug 12 08:15 UT to 20:45 UT) with maximum expected between 140.0 deg. and 140.1 deg. (Aug 12 13:15 UT to 15:45 UT). The IAU MDC list maximum at 140.0 deg.
The provisional plot from our multi-year results has a strong peak around sol. long. 140 deg., with a full width at half-maximum (FWHM) of at least 36 hours. (The dip at 140.0 deg. seems to be a genuine lull in our data). We’re already recording good numbers of bright Perseids, so even though maximum activity will occur during daylight from our longitude band the nights of August 11, 12 and 13 should give high rates, although the last quarter Moon will challenge visual observations and DSLR photography after midnight.
Clear skies,
Alex.