[Prev][Next][Index][Thread]
(meteorobs) [IMO-News] Leonid storm as seen from the UK
NOTE: Alastair is (for reasons unknown!) not a 'meteorobs' subscriber. If you
follow up, please MANUALLY put 'mcbal.gwyvre@virgindot net' in your "Cc:" line.
Forwarded without permission of the poster. Clear skies all!
Lew Gramer <owner-meteorobs@jovian.com>
------- Forwarded Message
Date: Fri, 17 Dec 1999 19:16:07 +0000
From: Alastair McBeath <mcbal.gwyvre@virgindot net>
To: imo-news@egroups.com
Subject: [IMO-News] Leonid storm as seen from the UK
SPA Meteor Section Results: Leonid storm as seen from the UK
By Alastair McBeath, SPA Meteor Section Director
Contrary to early media reports, the Leonid storm of November 17-18 was
indeed witnessed from parts of the UK. Now a month on from the great
night, it is possible to get a first impression of the view from the
British Isles.
To date 49 reports have arrived from various parts of Britain, 21 of
those indicating only cloudy skies, the remainder seeing something
meteoric on November 17-18. The positive reports include sightings of
probable fireball flashes in the overcast noted by a group with Mark
Bailey, Director of Armagh Observatory, in County Tyrone, Northern
Ireland. Several other locations recorded similar events, but Mark's
party were the only ones who were not able to spot even a few Leonids
directly as well.
The negative reports show southern and western England, Wales and
Northern Ireland came off worst for cloudy skies, rain and drizzle
including sites near Manchester, Birmingham and London and places in
Cheshire, Staffordshire, Bedfordshire, Oxfordshire, Wiltshire, Surrey,
Devon, Dorset and Sussex. However, conditions could be very variable.
For instance, soon after Leonid radiant-rise in London, a brief
cloud-break around 23h UT allowed nine-year-old Ami Frydman to spot a
lone, bright, probable Leonid meteor before the overcast set in for the
night there. Elsewhere, several observers in and around Manchester gave
up when clouds continued through until 04-05h UT on November 18, but Ian
Rigney's persistence paid off when skies unexpectedly cleared around
05:30 UT, and he managed a 40-minute watch until dawn twilight grew too
strong, still noting up to 2 Leonids a minute at times (though his
average observed rate was 1 Leonid per 4 minutes). Frustratingly, but
commonly among the reports from England and Wales south of Manchester,
Ian enjoyed far clearer skies on both November 16-17 and 18-19!
The luckier observers on November 17-18 were in Scotland and eastern
England. Positive sightings of the Leonids, often including the time
nearest the storm peak, have arrived from in and around Pitlochry,
Dundee, Glasgow, Edinburgh and Ayr in Scotland, and in Northumberland,
Tyne & Wear, Durham, Humberside and Lincolnshire in eastern England, and
there are unconfirmed reports of observations possible in Norfolk and
Essex as well.
With often a lot of cloud around even at the better sites, detailed
observations were frequently impossible, and many of the reports are
quite casual in nature. Even so, most people enjoyed what they could
see, and a clear peak in observed numbers is apparent in the available
sightings between about 01:50 and 02:40 UT, at its highest between
~02:00-02:15 UT in the more detailed counts from several watchers,
including Pam Foster in Pitlochry and Nick Martin with three other
observers near Ayr, for example.
Several people, including Tom Patton in Livingston and Eva Hans in South
Shields, commented that despite the cold, the excitement of seeing
numerous Leonids slipping down the sky in between the clouds, sometimes
in simultaneous groups, was enough to keep them warm and interested,
though as rates dropped, the delight in watching under cold skies waned
as well, especially after 03h UT.
One of the most fascinating reports came from three observers (Tom
Crann, Jeff Lashley and Dave Newton) from Sunderland Astronomical
Society, observing at Derwent Reservoir on the Durham-Northumberland
border. Aside from keeping an eye on the visual display, they attempted
some photography, but Jeff Lashley also secured 2h10m of video footage
covering the main storm peak, recording 20 of his 38 Leonids in the half
hour between 01:55-02:25 UT, in spite of mist and frequent clouds.
Just 40 km north-east of Derwent Reservoir at Morpeth in Northumberland,
my father Peter and I managed just under two hours of visual observing
between us, recording up to 8 Leonids a minute at best despite 55%
average cloud cover. We also caught 5 Leonid trails in 32 minutes of
photographic exposures, four faint events on a single 8-minute frame!
Using these trails plus eleven of Jeff's video Leonids, an approximate
Leonid radiant for November 17-18 around RA 150 degrees +/- 3 degrees,
Dec +21 degrees +/- 2 degrees has been derived. This compares very
favourably with the radiant recently derived by Sirko Molau from 633
Leonids in IMO video data at RA 153.6 degrees, Dec +21.9 degrees,
especially bearing in mind the much poorer skies the UK-only radiant
information was obtained under.
I would like to send my congratulations and many, many thanks to all
those who have reported results so far, including the numerous people
who have submitted datasets from outside the UK. There are far more
people than could be named here, but all who submit some results will be
mentioned in the Section's main published Leonid reports due out in
early 2000, with a more detailed overview of the shower as a whole, not
simply from Britain. Further observations would be most welcome too!
Alastair McBeath,
SPA Meteor Section Director.
Contact address: 12A Prior's Walk, Morpeth, Northumberland, NE61 2RF,
England, UK.
E-mail: vice_president@imodot net
------- End of Forwarded Message
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html