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BAA electronic bulletin
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PERSEID METEORS SHOW INCREASING ACTIVITY
With many places experiencing clear nights 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 annual meteor
calendar, producing an abundance of fast, bright meteors. Indeed there have
been a number of lovely Perseid fireballs reported already this year.
With full Moon on August 10, there will be considerable interference
by moonlight this year. Bright moonlight has an adverse effect on meteor
observing, and for a few days to either side of Full Moon, lunar glare
swamps many of the fainter meteors, reducing the total number of meteors
seen. Fortunately, the Perseid shower contains a high percentage of bright
meteors so there should still be a good show this month.
It should be remembered that a number of other, lesser showers are
also active at this time of year, such as the Delta and Iota Aquarids and
Alpha Capricornids, so there is plenty of interest for the meteor observer.
For details of all activity at this time, please refer to the Meteor Diary
in the 2014 BAA Handbook.
Video meteor systems recorded the first Perseid meteors in mid-July
and the shower will continue to be active until late August. 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 00h UT (01h BST) on August 13, coinciding with a waning gibbous Moon
in Pisces this year. Peak rates are likely during the night of August 12-13,
particularly in the pre-dawn hours of August 13.
Observers watching after midnight on August 12-13 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. Visual observers may minimize the effects of
moonlight by positioning themselves so the Moon is behind them and hidden
behind a wall or other suitable obstruction.
It is hoped that, weather permitting, observers will cover Perseid
activity on the nights leading up to maximum, particularly on August 10-11
and 11-12 and also after the peak on August 13-14. The Perseids are an ideal
target for digital imaging due to the relative abundance of bright meteors.
The best observed rates are usually noted 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.
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 2014.
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.
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:
meteor@britastro.org 2014 August 4
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