[BAA-ebulletin 00756] PERSEID METEORS APPROACHING PEAK ACTIVITY
(c) 2013 British Astronomical Association http://www.britastro.org/
Although the weather has been rather variable over the past few days, observers across the British Isles have reported increasing Perseid meteor activity. The Perseids are one of the most reliable showers of the year, producing an abundance of fast, bright meteors. This year there will be little or no interference by moonlight, with New Moon occurring on August 6 and First Quarter on August 14.
The first Perseid meteors were detected in late July and the shower will continue to be active until about August 21. The shower's activity displays a marked 'kick' around August 8-9 and steadily increasing observed rates may be expected from now until the peak, which is expected at around 18h UT (19h BST) on August 12 this year. This means that the two nights of Sunday night to Monday morning (August 11-12) and Monday night to Tuesday morning (August 12-13) will probably be equally productive for observers in the UK.
Observers watching after midnight on August 11-12 should experience increasing activity towards dawn, as the shower radiant at RA 03h 13m, Dec. +58? (near the Double Cluster, on the Perseus-Cassiopeia border) climbs higher in the eastern sky. Activity should be just starting to decline by the time darkness falls on Aug 12-13.
It is hoped that, weather permitting, observers will cover shower activity on the nights to either side of the maximum, for example on the Saturday night to Sunday morning (August 10-11) and Tuesday night to Wednesday morning (August 13-14). The Perseids are also an ideal target for digital imaging due to the relative abundance of bright meteors.
The best observed rates are found when the Perseid radiant is highest in the sky during the pre-dawn hours, but even in early evening the radiant is already at quite a favourable elevation above the horizon. Under cloudless skies, and in dark sites, observers can expect to see between 50 and 70 meteors each hour near the peak. Even in towns or cities observed rates may still be around ten an hour in the early morning hours when the radiant is high.
Observations in recent years have revealed noticeable variations in activity from year to year and we shall just have to wait and see what is in store for us in 2013.
The BAA's visual meteor report forms, available as downloads in both pdf and Excel formats, enable observers to record the details of each meteor seen. These include: time of appearance (UT); apparent magnitude (brightness); type (shower member, or random, 'background' sporadic); constellation in which seen; presence and duration of any persistent train. Other notes may mention flaring or fragmentation in flight, or marked colour. Watches should ideally be of an hour's duration or longer (in multiples of 30 minutes). Observers are reminded to carefully record the observing conditions and the stellar limiting magnitude.
For further information please see the August BAA Journal, page 187.
By whatever means you observe the Perseids this year, please submit your results to the BAA Meteor Section via meteor@britastro.org.
This e-bulletin issued by:
Dr John Mason
Director, BAA Meteor Section
email: docjohn@dircon.co.uk
2013 August 9