Society for Popular Astronomy

[Alastair McBeath]

Full Moon on August 6 means this year won't have a particularly auspicious Perseid maximum, though something of the shower's lower activity should still be visible in any clearer skies over the next few days at least, when there's no Moon.

The usual maximum is due between 17:30-20:00 UT on August 12. It should produce typically healthy Perseid numbers, with Zenithal Hourly Rates (ZHRs) around 80-100. However, Finnish meteor analyst Esko Lyytinen has suggested the Earth may encounter two denser meteoroid trails earlier on August 12, around 05:00 UT (laid down at parent comet 109P/Swift-Tuttle's 1862 return, though perhaps adding only 10 or less to the ZHR then) and 09:00 UT (from the comet's 1610 perihelion, adding between a few tens up to a hundred to the ZHR). Material scattered around these trails may lead to somewhat higher than normal Perseid activity for most of August 12 ahead of the ordinary maximum as well.

If correct, these timings will be about as unhelpful as possible for British visual observers, though radio observers here should still manage to follow something of the better activity, interference permitting. Visual watching throughout August 11-12 and 12-13, if clear, would be scientifically valuable, and potentially more rewarding certainly, despite the waning Moon (last quarter is on August 13). The Moon will visible nearly all night on both occasions, from before the Perseid radiant is first usefully-observable at about 22h UT for Britain. Even so, Perseid meteors should be relatively frequent enough, and many sufficiently bright, to mean some should still be seen around then. Keen watchers will need to observe as much clear sky as comfortably possible, without looking towards the Moon (hiding it behind a wall or roofline will help). Perseids are swift, often bright, and commonly trained meteors.

Additional information, including a Perseid radiant chart and details on the others showers active simultaneously, is available on the SPA's August monthly meteor webpage at:

http://www.popastro.com/sections/meteor/meteor-aug2009.htm .

Good luck & clear skies!

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

[markt]

Looking at the weather for the Perseids week for the UK, it's looking like we're all going to be in a mobile westerly airflow as low pressure sits to the northeast towards Scandinavia with the Azores high staying to the south of us. Breezy and showery springs to mind, with more showers in western parts. There could be more organised rain coming through at times but in between the showers and rain blue skies should be a plenty. So, whether we get to see the Perseids could be down to the ol' postcode lottery again and timings...
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Meade 5" Refractor, ETX90, Coronado SolarMax40, C8 XLT CF CaK PST
EQ6 Pro, 15x70's, 20x80's
Canon 350D, DMK31

[markt]

If you check out the International Meteor Organisation you'll see their live data is already showing the Perseids firing off at 20 meteors an hour as of 7th august http://www.imo.net/live/perseids2009/

This years rates are set to peak at about 200 meteors an hour on the 11/12th, so even with the waning moon there should still be a decent number to see.

It also looks like the weather may cooperate with us aswell, especially the further south you are in the uk.


_________________
Meade 5" Refractor, ETX90, Coronado SolarMax40, C8 XLT CF CaK PST
EQ6 Pro, 15x70's, 20x80's
Canon 350D, DMK31

[Alastair McBeath]

In respect of markt's recent note, UK observers need to be aware that as I mentioned in my original posting here, any Perseid ZHRs possibly as high as ~200 are predicted to fall during daylight for us (around 09h UT on August 12). Though this may mean activity should be rising towards the end of the night over Britain on August 11-12, the Moon and our relative distance from the maximum may leave the observed meteor activity relatively suppressed compared to such hopes. Of course, there's no guarantee anything unusual will happen at all, nor that it will keep to its predicted time (seven or eight hours early would be good!).

Regarding the weather, never rely only on weather forecasts when you're hoping to observe. Keep checking the sky where you are at regular intervals if it's cloudy (at least every half hour), since you never know when you might get a break.

And again - good luck!

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

[coldfieldboundary]

wrong topic ... ...
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Thanks to the clear cold nights...

[david entwistle]

[Alastair McBeath]

Like everyone else it seems, conditions have been less helpful in SE Northumberland for the Perseids so far this year too. Early August has continued the run of poor overnight weather seen for much of June and July here unfortunately, though the daytime weather has often been brighter and drier (it couldn't have been much wetter than July's!).

Pete Lawrence had some better luck, and has a posting with links to some images on the SPA Gallery Forum at:

http://www.popastro.com/phpBB2/viewtopic.php?t=12447 .

Thanks too to David for his radio meteor notes above. The IMO's "live" visual webpage has very little for the last couple of days as yet, and the ZHR values there seem remarkably low, probably in an effort to avoid over-inflating the Moon-affected raw data.

I made a couple of extended sky-checks in what "better" skies presented on August 10-11 and 11-12 for about twenty minutes each (around 01:30 UT on 10-11, and 23:20 UT last night), but the limiting magnitude (LM) was +4.9 on the first (with variable cloud at best giving just 40% clearer sky), and a mere +4.6 last, thanks to cirrostratus haze, making proper meteor observing impossible. I saw a couple of brighter Perseids (mags +1 and +2) only on Aug 11-12 in that time; not bad considering the extremely poor sky, but hardly awe-inspiring. There was a pleasing, pale, partial, 22° halo above the Moon on 11-12, but after 00h UT I caught only a glimpse or two of Vega and Capella through the thickening clouds, and no more meteors. Capella at 02h looked like a mag +3 star should under "normal" conditions!

If the usual maximum keeps to-time, around 17:30-20h UT today, we should catch part of the declining rates early-on tonight. The low radiant till after 22h UT won't help observed numbers then (unless this peak is late), but activity should be worth a look at least, assuming skies are as clear and dark as the weather and Moon will allow. Fingers crossed, especially for those who've seen very little of the Perseids so far this year!

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

[JohnM]

Despite the moon last night I managed to get some images of Meteors, probably Perseids but I have not worked the tracks out.

I used a Canon 40D 30s Exposure f2.8 17mm lens 800 ASA, I think that covers around 15% of the visible sky if my calculations are correct. Using computer control with intervals of 35s.

Results 587 images
15 Aircraft
1 Satellite (across 4 images)
4 meteors on 3 images between faint and very faint

Observation time from 21:30 BST 20090811 to 04:30 20090812 BST.

Bed at 05:30
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Engineer @ Work - Astronomer @ Play

[Alastair McBeath]

Excellent JohnM; look forward to more news once you've had time to work out what the meteors were!

Meanwhile, this is very preliminary news, so subject to later revision, but information reaching me this evening suggests the ~09h UT Perseid maximum prediction for earlier today (August 12) has been borne out in the radio and early imaging data. Radio observers in Europe and North America detected a clear, strong to very strong spike in echo counts around 07h-09h UT. The initial radio results are available via the Radio Meteor Observation Bulletin webpage at:

http://www.rmob.org/livedata/main.php

Jeff Brower in British Columbia, Canada, commented that this spike seems to have shown an excess of longer-duration echoes in his 10-minute data collection interval over 09h00m UT, than in the data bins to either side of this time, which may suggest more bright Perseids were present then. Jeff also reported his automated fireball video system recorded 28 bright events overnight on August 11-12. It's too soon to say whether there was a particular concentration of Perseid fireballs in these, or if they were clustered around 09h, however.

My grateful thanks go to Jeff for his very prompt provision of this information. And one last "good luck" to all for tonight!

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

[Bushy]

Hi all,

I thought I'd share my observations, for what they are worth, based on a 1 hour observation from 20.50 UT - 21.50 UT on 11th August from East Grinstead, West Sussex (bang on the Greenwich Meridian). Unfortunately, the limiting magnitude was around 3.6-4.0 (as the waning gibbous moon was rising and the street lamps were shining).

I saw 8 meteors in all, and although I can't verify their tracks, they all certainly semd to trace back by eye to Perseus. In addition, they all seemed Perseid like, in that they were fast, and 3 of them left a nice train, but this lasted only 3 or 4 seconds at most.

Not sure if this is useful info, but I had fun watching for them and it was cloudy last night (12th) so nothing extra to report.

Cheers

Bushy
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90mm Mak, cheapy 10x50 bins, lots of enthusiasm

[brian livesey]

Hopeless in the late evening at my observing site in the north-west, nothing but cloud. Very typical!
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brian

[Davej]

Hi
Same here Brian

Hi David Entwhisle, what equipment are you using to pick up these signals.

All the best.
Dave
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Meade LX 200 (7"). Odyssey 8" Dob.
11X80 10x50 15x70 bins
Celestron Neximage ccd cam

[Jonesy_1]

It cleared up a little over my neck of the woods (Stoke on Trent) at about 3:45 this morning and I did manage to see a couple of meteors despite the light pollution.

[Cliff]

Dear al(L)
I had it mind to give the Persieds a go for an hour or so probably starting 23:00 UT last night.
The previous few nights had been grotty and yesterday early evening was the same - it was grotty. I went to bed at 23:10 UT. The call of nature got me up at 03:00UT. I looked out, I could see the Moon partly obscured and Vega but little else astronomical wise. There was no dense blanket of cloud but nearly all the sky seemed covered by mottled cloud. I must admit I thought it might have been possible to see a few bright meteors between mottles but I went back to bed. Whether there were any decent observing spells at other times I cannot say (?)
Best of luck from Cliff

[Alastair McBeath]

Well, I did manage a proper meteor watch last night (August 12-13), though conditions were hardly ideal, with a LM of +5.2 and variable amounts of moonlit hazy and thicker cloud throughout. This increased rapidly and forced a premature end, so I was out for just 1h20m starting at 21:55 UT, with an average 25% cloud cover in my field of view. However, I spotted a baker's dozen of Perseids, plus a delightful mag -2 Kappa Cygnid dropping near-vertically down through thinner cloud to the NNE at 22:44, and three sporadics. Perseid of the night was a mid-flaring mag -3 fireball at 22:57 UT, probably in Cassiopeia (as it was partly in clouds...). Eight of my thirteen Perseids were of mag +1 or brighter, so the evening was quite pleasing, especially after the unhelpful skies earlier this month.

Towards the end of the watch, another partial 22° halo above the Moon started forming-up, which persisted, thanks to the perpetual cirriform cloud cover afterwards, for the rest of the night. By 02h UT, I was also able to spot a "new" fourth magnitude star low to the south - Jupiter in clouds...

Good to see I wasn't alone in enjoying something of the shower last night; well done to those who were lucky, and commiserations to those who weren't. The three main showers this autumn and early winter - Orionids, Leonids & Geminids - are all Moon-free, so there's plenty of meteor observing opportunities to come. [Just don't mention the weather...]

Perseid activity continues for another ten days or so, with rapidly lessening moonlight problems over the next few nights. Rates though tend to drop quickly once the peak is over, so while it's always worth a look to see what's happening with the latter stages of the shower, don't expect lots of meteors.

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