[BAA-ebulletin 00929] PERSEID METEOR OUTBURST EXPECTED

[Rick]

[BAA-ebulletin 00929] PERSEID METEOR OUTBURST EXPECTED
(c) 2016 British Astronomical Association    http://www.britastro.org/

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
2016 August 9