[BAA-ebulletin 00929] PERSEID METEOR OUTBURST EXPECTED

[BAA electronic bulletins service]

PERSEID METEOR OUTBURST EXPECTED

Every year in August, the Earth passes through the stream of dusty debris
from Comet 109P/Swift-Tuttle, the parent of the annual Perseid meteor
shower. The shower is among the most reliable of the year, producing an
abundance of swift, bright meteors visible over a two-week period of warm
summer nights. Some very nice bright Perseids have already been recorded
by members of the BAA Meteor Section during the rise to shower maximum.

This year’s Perseid display could well be even better than usual. Computer
models of the dust trails laid down by the parent comet at successive
returns to perihelion predict an outburst on the night of August 11-12
with peak rates of around 200 meteors/hour under clear, dark skies with
the radiant high in the sky. That is about twice as many Perseids as
usual.  The outburst is predicted to occur as the Earth crosses three or
more of these dust trails between about 22h UT on August 11 and 04h UT on
August 12. Careful observation will be required to ascertain when, or
indeed if, enhanced rates do occur.

This outburst will be in addition to the usual Perseid maximum, which this
year is expected during daylight hours from the UK on August 12.  Peak
Perseid activity this year coincides with a First Quarter Moon moving from
Libra into Scorpius, and setting before midnight, so conditions are rather
favourable. With the usual Perseid maximum expected at around 13h UT (14h
BST) on August 12, the period from Thursday night into the pre-dawn hours
of Friday morning (August 11-12) and from Friday night into the pre-dawn
hours of Saturday morning (August 12-13) are likely to yield the best
observed rates.


When to Observe

Meteor observing can be carried out by individuals, or by groups of
observers working together such as members of local astronomical
societies. The BAA Meteor Section welcomes reports from such groups as
well as individual observers.  Please refer to www.britastro.org/meteor.

On any night during the peak period, the best observed rates will always
be expected in the early morning hours, after midnight, as the shower
radiant (the region in the sky from which Perseid meteors appear to
emanate), at RA 03h 11m,  Dec. +58°, near the Double Cluster, on the
Perseus-Cassiopeia border, climbs higher in the eastern sky. Even in the
mid-evening, however, as darkness falls, the radiant is already at quite a
favourable elevation above the horizon.  Just face in the opposite
direction to the Moon (if it is still above the horizon) so that you are
looking into a dark sky.

Under cloudless skies, and from a dark viewing site, observers can expect
to see between 50 and 70 meteors each hour near the peak. Even in light
polluted towns or cities, observed rates may still be around ten meteors
an hour in the early morning hours when the radiant is high. Activity
should be starting to decline by the time darkness falls on the evening of
August 13.

Meteor observing should be viewed, first and foremost, as a source of
enjoyment for the observer(s). Whatever the approach and specific
techniques applied, meteor observing can still produce unexpected results,
and the only way to make sure you don’t miss out is to go out and observe!

By whatever means you observe the Perseids this year, please submit your
results to the BAA Meteor Section via meteor at britastro.org.


This e-bulletin issued by:

Dr John Mason
Director, BAA Meteor Section
email: docjohn at dircon.co.uk

2016 August 9