Society for Popular Astronomy

[Alastair McBeath]

Although the run of strong to storm Leonid returns seen from 1998-2002 is unlikely to repeat again until the 2030s (or perhaps even till next century), independent model calculations by David Asher, Esko Lyytinen & Marku Nissinen, Mikhail Maslov and Jeremie Vaubaillon have indicated 2009 may bring strong rates again. Various possible maxima and Zenithal Hourly Rate (ZHR) strengths have been proposed, primarily due to dust trails left by the shower's parent comet 55P/Tempel-Tuttle at its 1466 and 1533 returns, with the better peaks expected between roughly 20:40 to 22:00 UT on November 17.

Esko & Marku have suggested the 1466 trail may produce ZHRs above 20 from about 06:30 UT on November 17 till 00:30 UT on November 18, with a denser dust region likely producing ZHRs above 40 from circa 16h-23h UT on the 17th. This denser 1466 region will probably combine with the 1533 trail to push ZHRs up perhaps towards 150 or higher at some stage between 21h-22h UT that day. A recently-published re-evaluation by these two analysts in the August issue of the International Meteor Organization's (IMO's) journal WGN has suggested the peak ZHR may be somewhere between 150 to 300, centred around 21:28 UT on November 17. Mikhail has suggested ZHRs should peak between 21h-22h UT then too, at ~130-140. Jeremie's modelling has been revised yet more recently, following the Earth's encounter with the 1466 dust trail in 2008. Unfortunately, this has led to the downgrading of what he originally thought could be storm-proportion rates to probably 'only' strong activity. The time such rates are anticipated has altered hardly at all in this fresh examination however, suggesting ZHR peaks on November 17 around 21:43 (1466 trail; ZHR ~115) and 21:50 UT (1533 trail; ZHR ~80). The proximity of these two encounters may mean combined rates of about 200 could occur briefly. The 1466 encounter may happen between 30 to 60 minutes later than this though.

Aside from these main events, other less active submaxima may occur as well, on November 17 around 07:27 (ZHR maybe ~25; the timing marginally adjusted, and the strength of this event also now greatly downgraded by Jeremie) and 09h UT (ZHR ~25-30), and on November 18, at about 00:04 (~15), 03:29 (1102 AD trail; low rates?) and 19h UT (~10-15, probably of faint meteors). The Earth passes closest to the node of the comet's orbit just after 15h UT on November 17, with a likely ZHR of ~10-20.

Clearly, the evening to early morning UT hours of November 17-18 will create most interest for watchers, but none of these predictions is guaranteed of course, nor can other unexpected peaks be ruled-out. Whatever takes place, new Moon on November 16 ensures perfect viewing conditions.

The Leonid radiant rises only by ~23h UT, and reaches a fully usable elevation after midnight from Britain. Consequently, we will likely miss the very best Leonid activity, if the predictions are accurate. However, watching from the UK will probably be most rewarding towards dawn on November 16-17, plus around and shortly after radiant-rise on November 17-18. Coverage at times when the radiant is readily-seen on these nights, and others, would be important as well, and could catch any unanticipated peaks. If the 1466 trail peak is an hour later than predicted, so around 22:45 UT on the 17th, and does produce rates of 100+, one or two Leonids might be seen near then from Britain, at or shortly before radiant-rise. Such meteors would be very long-pathed, so might seem to be moving slower than the usually very swift Leonids should do, while heading away from the radiant area as normal. Worth looking out for, just in case.

For more information and a Leonid radiant chart, see the November meteor activity webpage at:

http://www.popastro.com/sections/meteor/meteor-nov2009.htm .

Good luck, and clear skies!

Alastair McBeath,
Meteor Director, Society for Popular Astronomy.
E-mail: <meteor@popastro.com> (messages under 150 kB in size only, please)

[Graham]

I got an invite to this event on Facebook

[andyT]

hi guys looking forward to this,lets hope as always the weather plays ball.
andy
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4'' refractor
zeiss 10x50,
helios 11x80.
Leica BN 8x32,
Helios 13-40x80 bins

[Alastair McBeath]

Graham: You're right. Jeremie Vaubaillon has drastically reduced his expectations for strong meteor activity from the Leonids now. However, there's no harm in watching and hoping - assuming the weather cooperates on November 17-18!

Alastair McBeath,
Meteor Director, Society for Popular Astronomy.
Meteor homepage: http://www.popastro.com/sections/meteor.htm
E-mail: <meteor@popastro.com> (messages under 150 kB in size only, please)

[cacmcgoo]

Weather for sw England looking alright. Fingers crossed.
Metcheck website reliable and detailed.

Tom
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Celestron 15x70
Looking for mak cass

[david entwistle]

[cacmcgoo]

still clear here in corsham, with 2 or 3 friends coming over to help count from 8.30 - 10.00pm or so.
Fingers crossed!

Tom
_________________
Celestron 15x70
Looking for mak cass

[Astrocomet]

Very clear outside this evening so I hope to go out around 22.00 hours U.T when the Sickle shape of Constellation of Leo is well risen in the Eastern Sky-Orion dominates it at the moment.

I usually get to see plenty of bright Meteors in the early hours once people start to turn in for the night and Domestic lighting starts to abate in most areas-anyway lets hope for some real fizzlers with orange heads and green trains that curl up like a snake-seen several type of these Leonids in years gone by....
_________________
Colin James Watling
--
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)
Web: http://lyra.freewebsites.com/
www.lyrandgyastronomers.blogspot.com/

[Alastair McBeath]

I'm sorry to see no positive Leonid reports from Britain here as yet, though I'm hardly surprised after the rest of this soaking autumn. Little luck here in Northumberland either sadly, thanks to yet more dismal weather. I did manage to spot a solitary magnitude -1 Leonid, with a pleasing 3-second train in the only cloud-break after radiant-rise on November 16-17, a twenty-minute spell after 23:25 UT (sky limiting magnitude +5.5). Nov 17-18 started out partly clear and hazy once the evening rain had cleared, but conditions simply worsened later, and the sky was overcast by 23:00, with yet more heavy rain for the rest of the night.

The "live" IMO Leonid results page is at:

http://www.imo.net/live/leonids2009/ ,

which suggests already that places elsewhere enjoyed both clearer conditions, and healthy Leonid activity. Too early to say how this compared with the predictions, but ZHRs of 100+ have featured there already during November 17.

It's probably worthwhile keeping an eye out in any clearer skies after midnight for the next night or two, in case anything unusual might still happen from the shower, but otherwise it's back to hoping skies will be better for the Geminids next month...

Alastair McBeath,
Meteor Director, Society for Popular Astronomy.
Meteor homepage: http://www.popastro.com/sections/meteor.htm
E-mail: <meteor@popastro.com> (messages under 150 kB in size only, please)

[Matthew_Phipps]

I was able to observe 3 meteors between 2 35am and 3am on Tuesday morning. One of these I believe not to have been a Leonid.
I observed until 4am seeing nothing else.

From 5 30am until 6 45am (again on Tuesday 17th), I was outside and was able to observe 6 Leonids in this period. 5 of these I saw within about a 10 minute spell sometime between 6 and 6 15am, and were all quite impressive given the brightness of the sky at that point.

I was happy to finish the night on a high... but equally I was left very disappointed that those 5 leonids alone suggested there was possibly something quite spectacular building.

These observations were made in a clear, but heavily light polluted sky in Hertfordshire.

On Tuesday night I was outside from 9-10pm in a very patchy sky, but observed nothing before the clouds settled in for the night.

-Also I came across this video on the BBC website of a fireball seen over Utah on Wednesday:
http://news.bbc.co.uk/1/hi/sci/tech/8367760.stm

[Alastair McBeath]

Matthew: Many thanks for your notes. Central-southern England seems to have had some of the better skies on Nov 16-17 from the reports reaching me so far (Leics, Worcs & Oxon aside from yourself), with the following night apparently being very poor across most of Britain.

I've sent some preliminary notes on the Leonids (plus the full Orionid report) for the SPA's Electronic News Bulletin which should be issued tomorrow, all being well. The ENBs are available freely to anyone who'd like to see them, not just SPA members, and you can subscribe to them from the SPA's homepage, http://www.popastro.com . There's also an archive of previous ones elsewhere on the Forum.

Of greatest UK-observer significance perhaps is that I've had two reports of a brilliant Leonid fireball at 05:47 UT on November 16-17, made from Lancashire and Co Londonderry. Details are a little sketchy so far, but the object's ten-minute long persistent train was imaged from Northern Ireland, which images can be seen, with other comments on the shower - including some positive British reports! - on the UK Weather World's Space Weather Forum at:

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=33351&posts=7&start=1 .

If anyone else spotted this fireball, or indeed any others - meteors of magnitude -3 or brighter - from the British Isles or nearby, I'd welcome seeing a full report as soon as possible. The minimum details I need are:

1) Exactly where you were (name of the nearest town or large village and county if in Britain, or your geographic latitude and longitude if elsewhere in the world);

2) The date and timing of the event; and

3) Where the fireball started and ended in the sky, as accurately as possible, or where the first and last points you could see of the trail were if you didn't see the whole flight.

More advice and a fuller set of details to send (including an e-mail report form) are on the "Making and Reporting Fireball Observations" page of the SPA website, at:

http://www.popastro.com/sections/meteor/fireball.htm .

Excellent to see so much interest was generated by the Leonids this time here, even if our combined enthusiasm wasn't enough to clear the skies...

Alastair McBeath,
Meteor Director, Society for Popular Astronomy.
Meteor homepage: http://www.popastro.com/sections/meteor.htm
E-mail: <meteor@popastro.com> (messages under 150 kB in size only, please)

[Lady Isabella]

[Alastair McBeath]

Lady Isabella: As I've had no report on this fireball from you still, can you send me some details please?

Alastair McBeath,
Meteor Director, Society for Popular Astronomy.
Meteor homepage: http://www.popastro.com/sections/meteor.htm
E-mail: <meteor@popastro.com> (messages under 150 kB in size only, please)