Meteor Showers List
Introduction
This is the separate listing of meteor showers referred to on page 4 of the Section's booklet
Observing Meteors. Section members are encouraged to observe these because they are known
to be genuinely active at the present time, and they produce visually-detectable rates.
The list is based on the 1995 revision of the International Meteor Organization's (IMO's)
Working List of Visual Meteor Showers, itself based on the most accurate global datasets
ever collected, from 1988-1995. Amendments have also been made using data collected since 1995,
to ensure the listing is as fully up-to-date as possible.
As we have discovered particularly during the last decade, meteor showers are not fixed things,
but are in a constant state of flux and change, some changing faster than others. As our
understanding of their activity continues to improve, so we continue to refine the details on
individual meteor showers. The information presented here was correct as of 2006 March 7. The
showers are listed in order of their maximum dates.
SPAMS Visual Meteor Shower List
Shower Comments
The Quadrantids are named after the now-discarded constellation of Quadrans Muralis, the Mural Quadrant,
which has been amalgamated into northern Bootes. Their peak is very short-lived, lasting only a few hours,
and can be easily missed. It is expected around 00h30m UT on 2007 January 3-4, but with a full Moon visible
all night. Peak ZHRs are occasionally variable (the highest recently was 180 in 1992), and a second, lesser,
maximum has been found sometimes, mainly in radio observations, since 2000, about 9-12 hours after the main
peak. Medium-speed meteors.
The Virginid complex of radiants have their centre of radiation given for March 24. Slow to medium-speed
meteors.
Best Lyrid rates are normally ~15-20, but short-lived, more active bursts are sometimes recorded, most recently
in 1982 (ZHR = 90). The maximum time can vary (expected between roughly 08h30m to 19h00m UT on April 22 in 2006,
in daylight for Britain, but with a favourable last quarter Moon). Medium-speed to swift meteors. Probable
parent body is Comet Thatcher of 1861 (orbital period about 415 years).
The η Aquarids are never easy to observe from the UK, as their radiant rises shortly before dawn, but
occasional members are spotted by British watchers. Activity is marginally easier to note from these latitudes
after the peak, when the radiant rises a little earlier. Very swift meteors, often with long paths because of
their low radiant, and fine persistent trains. The stream was laid down by Comet 1P/Halley, along with their
autumn twin the Orionids. Halley was last at perihelion in 1986 (period around 76 years).
The Sagittarid stream complex centre is shown for May 20. Note that for this shower only, the daily declination
change has a "+" sign both before and after this date. Slow to medium-speed meteors.
The June Bootids produced an unexpected outburst in 1998, when ZHRs of 50-100+ were observed for over 12 hours,
but rates were seen on just one date. Before this, only three returns of the shower were known, in 1916, 1921 a
nd 1927. Another ZHR 50 outburst happened on 2004 June 23. The shower is associated with Comet 7P/Pons-Winnecke.
New Moon on June 25 favours checking, even if June's all-night twilight does not.
The minor Pegasids are difficult to observe from Britain because of early July's all-night twilight, and this
year, an almost full Moon. Very swift meteors. Not found at all in a recent global video analysis.
The Southern δ Aquarids are the strongest of all the summer Aquarid/Capricornid showers, but none are too
well seen from the UK, as their radiants are south of the celestial equator. Care must be taken to separate the
various sources in this part of the sky in July-August. Medium-speed meteors. New Moon on July 25 is excellent
news for visual observing of the late July shower peaks this year.
The α Capricornids occasionally produce beautifully bright meteors, but their activity is never very
high. Slow meteors.
The Southern ι Aquarids are very weak visually, and may well be better-seen telescopically. Slow to
medium-speed meteors. Bright waxing Moon.
The Northern δ Aquarids are weaker than their southern counterpart, but are again medium-speed meteors.
Full Moon.
From 1988-1999, the Perseids produced a double maximum, but from 2000-2003 only one main peak was seen. The
primary peak was associated with Comet 109P/Swift-Tuttle's perihelion in 1992. A strong, early peak recurred in
2004. The normal maximum this time is expected on August 12-13 between 23h-01h30m UT, perfectly-timed for
Britain, but with a bright waning Moon. Predictions made some years ago suggest rates may be somewhat enhanced
this year again, but probably less strongly than in 2004. Swift meteors, often trained.
κ Cygnid rates are generally low, but occasional bright fireballs (possibly in periodic bursts every 6-7
years) have been seen from this source. Slow meteors. Virtually Moon-free.
Like their southern twin, the Northern ι Aquarids may well be a more active telescopic shower. Medium/slow
meteors. Nearly-new Moon.
The α Aurigids (possibly associated with Comet Kiess, last seen in 1911; period around 2000-2500
years), are part of a series of suspected minor showers with radiants in Aur, Cas, Per, Ari and Tri during the
early autumn. All appear to be most active from late August to mid-September, and need more investigation.
Very swift meteors. Favoured by an early-setting waxing gibbous Moon.
δ Aurigids are very similar to α Aurigids; swift meteors, but peaking slightly later in September.
A second, weaker, peak (ZHR 3) occurs around September 23-24. The first is hopelessly moonlit, the second very
favourable.
Piscid rates are usually low, but add to the interest in September. Slow meteors. Moonless.
Draconid showers are rarely recorded away from their parent comet 21P/Giacobini-Zinner's perihelion years
(period around 6.6 years), as most recently in 1998, when short-lived ZHRs of some 700 occurred. Other returns
have given rates up to storm levels (in 1933 and 1946). A largely unexpected outburst happened in 2005 (ZHRs ~35;
the comet returned that July), so worth checking in most years just in case. Slow to very slow meteors, and
apparently very fragile meteoroids. Possible maxima in 2006 fall on October 8-9 between 14h-07h UT.
Complete with an almost full Moon, sadly.
The Orionids are linked to Comet 1P/Halley, like their May counterpart, the η Aquarids. ZHRs are usually
quite good for 2-3 nights centred on their peak, and may be about 20-25 this year, from a recent analysis.
Quite strong sub-maxima have been noted around October 17-18 as well (crescent Moon). Very swift meteors,
with good trains. The main peak falls almost at new Moon.
The Southern and Northern Taurids are both associated with weakly-active Comet 2P/Encke, which has the shortest
orbital period of any comet known (3.3 years). The two showers give low rates, but occasional fireballs spice
up their prospects, and in some years (as last in 2005) these can be especially prevalent in late October to
early November (mostly moonless, but nothing unusual is predicted this time). Slow meteors. Full Moon on November
5 spoils both maxima this year.
Heightened Leonid activity is possible in 2006, after a dip in rates since the strong to storm returns of
1998-2002, associated with parent comet 55P/Tempel-Tuttle's perihelion passage in 1998. The potential peaks
may fall near 21h UT on November 17-18 (ZHRs maybe 10-20+, but before radiant-rise, circa 23h, for Britain),
and around 04h45m-04h50m UT on November 19 (ZHRs perhaps 100-150?). Other potential maxima during the shower
are not excluded, however. Moonless. Leonids are very swift meteors, almost as fast as meteors can be, and
still be members of the Solar System. Many leave good trains which can be exceptionally long-lasting.
The α Monocerotids have a suspected periodicity of ten years between their high, short-lived outbursts.
The most recent one was in 1995, very well-seen across Europe. Estimated ZHRs were around 420, but for only
about five minutes; the whole outburst took less than half an hour! However, no outburst recurred in 2005,
so the periodicity is unproven. Observers need to be alert every year, just in case. Very swift meteors.
The maximum is due at 21h05m UT on 2006 November 21, about two hours before the radiant can be usefully
observed from the UK, but Moon-free.
The Geminids are associated with asteroid 3200 Phaethon, rather than a comet, and their meteoroids seem to
be rather denser than those in most meteor showers too. Reliably good rates can be seen for around two nights
over their peak, but drop away very quickly after the maximum itself. Medium-speed, and often bright, meteors.
Their peak is due on 2006 December 14, within 2h20m of 10h45m UT, badly-timed for British watchers, and with
a waning crescent Moon rising near 01h on nights to either side, but some dark-sky watching of the near-peak
rates should remain possible.
The minor Coma Berenicids are poorly-known, and badly need more observing. Very swift meteors. Perfect for
December's new Moon.
The Ursids are linked with Comet 8P/Tuttle (period around 13.5 years; next at perihelion in late December 2007).
Their peak rates can be quite variable from about 10-50, with especially good activity last in 1986. Medium
to slow meteors. The maximum on December 22 is due near 19h-22h UT, excellent for Britain, complete with no
Moon!
