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Monday, 3 October 2011


BAA electronic bulletin
This is an announcements only list - please do not reply to the list address.


The October issue of the Journal will hopefully have alerted all BAA members
to the possibility of an unusual outburst of Draconid meteors on the evening
of Saturday, 8 October 2011.  The meteors are connected with periodic comet
21P/Giacobini-Zinner, so the shower is also known as the Giacobinids.

As the Journal article explains, the Earth intersects a number of dust
trails laid down by the parent comet during the evening of 8 October.  The
first and most probably weaker outburst, due to a number of rather old
trails, is likely to occur sometime after 16h UT, but the timing is
uncertain and will favour observers in Eastern Europe and the Middle East.

The second and most likely stronger outburst is interesting because it
involves the 1900 and 1907 dust trails that were responsible for the great
Giacobinid showers in 1933 and 1946.  Peak activity due to these trails is
likely to occur sometime between 19h and 21h UT but the outburst, if it
occurs, is likely to be sharp and brief.  Observations across all longitudes
are important, but it will be essential for would-be observers to be far
enough north to ensure that the radiant is at a respectable altitude above
the horizon during the period of potential activity.

The peak rates of these outbursts are highly uncertain, but no meteor storm
is likely.  Estimated peak levels of meteor activity range from 40 meteors
per hour to 800 meteors per hour.  The only way to find out what happens is
to go out and look for yourself!

Unfortunately, there will be a waxing gibbous Moon in Aquarius, less than
four days from full at the time of peak Draconid activity, so there will
some interference from moonlight.  Observers are therefore advised to direct
their gaze to the northern half of the sky, keeping the Moon behind them.

The radiant of the shower will be centred near RA 17h 32m, Dec + 55.5o, not
far from the star Nu Draconis in the 'head'of Draco. Throughout the period
of likely activity of the shower (16h to 22h UT), the radiant will be at a
respectable altitude above the north-western horizon - and it is on a
Saturday evening!  Draconid meteors are typically very slow moving, in
marked contrast to members of showers such as the Perseids or Leonids.

>From the British Isles, observers should go out as soon as twilight falls on
the evening of Saturday, 8 October.  Sunset is 17:23 UT from London; 8
minutes later from Edinburgh.

Observations will also be of considerable value on the evenings immediately
before and after the predicted peak to provide a check on background meteor
rates at this time. Let us hope for clear skies everywhere on the evenings
of 7, 8 and 9 October 2011, but particularly on the 8th!

The BAA Meteor Section would welcome any observations of the Draconid meteor
shower this year from individuals or local society groups, using any of the
observing methods outlined on the BAA website.  Visit
and click on the link under 'Join our Draconid Meteor Watch Project'.   Even
simple counts of meteors seen within given time periods will be welcome.

It is intended that a summary of all the observations received, crediting
all of the individual observers and society groups, will be published in the
Journal as soon as possible after the event.

Dr John W Mason

Director, BAA Meteor Section

30th September 2011

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(c) 2011 British Astronomical Association


Good Clear Skies
Colin James Watling
Various Voluntary work-Litter Picking for Parish Council (Daytime) and also a friend of Kessingland Beach (Watchman)
Real Astronomer and head of the Comet section for LYRA (Lowestoft and Great Yarmouth Regional Astronomers) also head of K.A.G (Kessingland Astronomy Group) and Navigator (Astrogator) of the Stars (Fieldwork)
Information -- More Info -- And More Info

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