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2011 Perseids

(Report copied from SPA Forum)
 
The initially gloomy picture of how observing the shower's moonlit peak went from Britain has changed little. In general, the better night close to the peak was August 14-15, if chiefly for a few lucky places in southern Britain. Some people spotted the occasional Perseid in cloud-gaps in southeast England on August 13-14 as well, but elsewhere, solid overcast was the norm. Fortunes were mixed too for the SPA Meteor Section's overseas contributors, with many fewer people able to observe near the shower's maximum than might have been hoped. There was some better coverage of the early Perseid activity in late July and early August, which nicely confirmed the typical slow rise of shower rates during that time. 
 
Observers who contributed either directly or through the SPA and UK Weather World's Space Weather Forums - the latter at: 
http://www.ukweatherworld.co.uk/forum/index.php?/topic/85826-perseids-2011
 
included (visual reports only, unless noted): "Bluebreezer54" (England), "Cliff" (England), Mike Feist (England), Len Entwisle (England; via September's "The Astronomer", TA, courtesy of Meteor Editor Tony Markham; see: http://www.theastronomer.org ), Valentin Grigore (Romania), "GroovySciFiChick" (England), Bill Haddon (California, USA), Heart of England AS (England; in September's TA), Alan Heath (England; radio), "Leo S" (England), Tony Markham (England; also in August's TA), John Mason (Wales), "scrapemedic" (England) and "waspy" (England). North American Meteor Network contributors, data kindly forwarded by Rich Taibi, included: John Drummond (New Zealand), George Gliba (West Virginia, USA), Paul Jones (Florida, USA), Robert Lunsford (California, USA), Bruce McCurdy (Alberta, Canada), Pierre Martin (Ontario, Canada), Paul Martsching (Iowa, USA) and Wesley Stone (Oregon, USA). 
 
Radio results were taken from Radio Meteor Observation Bulletin (RMOB) 217 for August 2011, provided by Editor Chris Steyaert - see http://www.rmob.org . Observers active across the expected Perseid peak were: Enric Algeciras (Spain), Mike Boschat (Nova Scotia, Canada), Jeff Brower (British Columbia, Canada), Willy Camps (Belgium), Johan Coussens (Belgium), Gaspard De Wilde (Belgium), Franky Dubois (Belgium), Karl-Heinz Gansel (Germany), Peter Knol (Netherlands), Mike Otte (Illinois, USA), Steve Roush (Arizona, USA), Andy Smith (England), Chris Steyaert (Belgium), Dave Swan (England) and Felix Verbelen (Belgium)
 
With too little data available to carry out a useful analysis visually, notes here are solely from the IMO's "live" results page. Overall, Perseid activity seemed somewhat disappointing this year by modern standards, with what would have been a vintage return during much of the 1970s, peak ZHRs around 50-60 on August 12-13. It's unclear what effect the Moon may have had on these values, perhaps hiding many of the fainter meteors that could have raised the activity level substantially, though this seems a reasonable ball-park figure for the shower's likely best from the results available. 
 
The Section's radio analysis identified a clear peak on August 12-13, although with most of the viable datasets available just from Europe, the maximum timing could be only tentatively suggested as probably between roughly 01h-04h UT on August 13th, especially around 04h. A potential secondary resurgence to a somewhat lesser level was apparent around 07h-08h UT, but caution is needed here, because both the 03h-04h and 07h-08h intervals were close to the shower's best-observable times for radio systems in Europe, as well as lying either side of the diurnal ~06h sporadic activity peak, which also distorts the radio activity graphs around this time of day. Overall though, a general confirmation of the visual data was implied, if perhaps the relative strength of the radio maximum could also have indicated somewhat better rates than the visual observers found. In turn, that may have been due to better numbers of faint meteors in the stream's peak. A much stronger "real" return could not be supported by the radio data even so. 
 
As always, my most grateful thanks, and those of the Section go to all our contributing observers and correspondents for their efforts during this year's Perseids, regardless of their level of success! 
 
Alastair McBeath

Added by:  Tracie Heywood