This is the separate listing of meteor showers referred to in the Section's booklet Observing Meteors. SPA observers are encouraged to cover these showers because they are known to be genuinely active at the present time, and they produce visually-detectable rates. The list is based on the 2010 revision of the International Meteor Organization's (IMO's) Working List of Visual Meteor Showers, itself based on the most accurate global datasets available from 1988-2009, and includes theoretical predictions for the current year which may vary from what was detected in the past. Amendments continue to be made using reliable data to ensure the information remains as fully up-to-date as possible, since as we have discovered in the last two decades, meteor showers are not fixed things, but are constantly changing, some faster than others. The details presented here were correct as of 2012 January . Except for the Antihelion Source, the remainder are listed and discussed below in order by their date of maximum.
In addition to the variations in meteor rates due to major meteor showers listed later, there are also general daily and seasonal trends in meteor rates. In the same way as the front of your coat gets wetter than the back as you walk through the rain, so the side of the Earth facing the direction the Earth is heading its orbit encounters more meteors than the backward looking side. In practice this means that the background sporadic meteor rates are lowest at around 6pm each day and then steadily rise through the night towards their peak at around 6am. The seasonal variation occurs because the direction in which the Earth is moving lies on the ecliptic 90 degrees behind the location of the Sun. Around the spring equinox, this is in Sagittarius and so never gets very high in the sky from the UK and so sporadic meteor rates are low. By the autumn equinox, this has moved to the Taurus/Gemini area, is therefore much higher in the sky, and hence we see higher sporadic meteor rates.
Source is active all year except during STA & NTA; Better ZHRs (3-4) likely in March-April, early & late May & June, and early July; Radiant area is about 30° in RA by 15° in Dec.
Quadrantids: Named after the disused constellation Quadrans Muralis, the Wall Quadrant, now amalgamated into northern Boötes. The peak lasts only a few hours, so can be easily missed, while the radiant, though circumpolar from Britain, is very low in the evening hours, rising overnight to be highest towards dawn.
Unfortunately in 2013 the Quadrantid peak is expected to occur around 12-13h UT on January 3. In addition, although the nights will start moonlight-free, the near last quarter Moon will rise in the late evening in the Leo-Virgo area on Jan 2. Despite the presence of moonlight, it is likely that UK based observers will see the best observed rates late in the night of Jan 2-3. Observers at the more northerly latitudes who can observe before 17h UT may also see reasonable rates during the decline from the peak. Quadrantid meteors are typically of medium speed.
The peak ZHR is usually in the region of 100, but stronger peaks have been seen occasionally (recent highs were 180 in 1992 and 160 in 2008 - for the latter only, see ENBs 236
), and a second, lesser, maximum has been found sometimes since 2000, mainly in radio observations, about 9-12 hours after the main peak. Thanks to recent IMO video reports indicating weak activity is apparently present from December 28 to January 12, the shower's activity period has been extended accordingly, though it is likely visual observers will struggle to see any Quadrantids other than on a few nights either side of the maximum, as this was typically the case in the past.
The chart below shows the Quadrantid radiant location
Lyrids: Background meteor rates are generally low for northern hemisphere based observers during the first half of the year. The Lyrids stand out above this. Peak rates are normally ~15-20, but short-lived, more active bursts have been recorded sometimes, most recently in 1982 (when ZHRs were ~90). Lyrid meteors are typically medium to swift speed. The probable parent body is Comet Thatcher of 1861 (whose orbital period is about 415 years).
In 2013, Lyrid maximum is predicted for approx 11h UT on April 22. Unfortunately, Full Moon occurs on April 25 and during the night of Apr 21-22 the 83% illuminated waxing gibbous Moon will be on the Leo/Sextans border and, from the UK, will not set until morning twilight is underway.
The radiant (see below), lies on the Hercules-Lyra border at the peak (and not as near Vega as some people expect). It is low in the sky at the start of the night and gains altitude as the night progresses, leadinmg to increasing observed rates.
η Aquarids: This shower is never easy to see from the UK, as its radiant rises shortly before dawn, about 01:30 UT, but occasional members have been spotted by British watchers. Activity is marginally easier to note from these latitudes after the peak, when the radiant rises a little earlier. An excellent shower in pre-dawn dark skies from the southern hemisphere though, and the rates, which may be variable, could be only a little down on their possibly cyclical highest in 2012 (variable ZHRs from ~40-85). Rates often remain good for several days across the maximum too.
At maximum in 2013, the Moon will be a waning crescent near the Aquarius-Pisces border. Eta Aquarids are 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).
: An unpredictable source, the June Boötids produced an unexpected outburst in 1998, when ZHRs of 50-100+ were observed for over 12 hours, with rates seen on just one date. Before this, only three returns of the shower were known, from 1916, 1921 and 1927. Another ZHR ~50 outburst happened on 2004 June 23, but a similar event predicted for 2010 June 23/24 proved disappointingly very weak (ZHRs < 10; see ENBs 291
). The shower is associated with Comet 7P/Pons-Winnecke, last at perihelion on 2008 September 26. The Full Moon of June 23 will be low in the sky and so will add little to the problem of Britain's short, twilight midsummer nights for watchers - and even casual observers here easily spotted the 1998 return. No activity is expected this year, though recent IMO video results have indicated very weak rates may happen annually from the shower, on or around June 24, so worth keeping watch then just in case, and also around the 1998 peak's repeat time, on June 27. The June 24 video June Boötids were radiating from an area about 10° south of the expected one, however. June Bootids are typically very slow meteors.
δ Aquarids: This shower (referred to as the southern Delta Aquarids in many listings) is not seen at its best from the UK, thanks to its southerly radiant. Great care must be taken to separate d Aquarids from ANT and CAP meteors in July-August. Minor adjustments to their "last active" and maximum dates were made for 2011, though the better rates may persist at similar levels from July 28-30 anyway.
This year, the Moon will be between Full and Last Quarter on the night of maximum and so will hinder observations. Delta Aquarid meteors are typically of medium speed.
α Capricornids: These are typically slow meteors, occasionally beautifully bright, but their activity is never very high. With the Moon having been at Last Quarter on July 29, moonlight will hinder observations in the later part of the night. The shower radiant actually overlaps that of the ANT and this has caused problems for visual observers recently, who have struggled to identify the CAP as a distinct source.
: 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 most recent perihelion in 1992 (period ~130 years). Highest activity between 2004-2010 has been variable, with average ZHRs from ~80 to 180 in different years (180 in 2009 only, perhaps topping-out around 230 briefly; see ENBs 273
), and sometimes with several maxima. The shower is rich in bright meteors, with around a third of Perseids leaving persistent trains.
No predictions of an enhanced peak are in-force for 2013, with the normal maximum due on Monday August 12 at around 18hUT, For UK based observers, the best observed rates will probably be seen late in the night of Aug 12-13, with high rates also during Aug 11-12 and good rates also likely during Aug 13-14. Moonlight conditions will be unfavourable in late July for the early Perseids but, with New Moon occurring on Aug 6, much of the early August rise towards the peak will occur in dark skies. Indeed, although the Moon will be approaching First Quarter on the night of maximum, UK observers will have little problem with moonlight as the Moon will be located near the Virgo/Libra border and setting at around the end of evening twilight.
Having passed by the Double Cluster earlier in the month, the Perseid radiant (see below) lies close to the Per/Cam border at maximum.
κ Cygnids: Rates are generally low and meteors are slow, but occasional bright fireballs (possibly in periodic bursts every 6 to 7 years) have been seen from this source. Recent IMO video results have indicated the maximum may be nearer Aug 14 (rather than Aug 20) and also found problems in defining the radiant position. The Moon, at First Quarter on Aug 14 and Full on Aug 21, will hinder observations to some extent this year.
September Minor Showers: Although no major meteor showers are active during September, background meteor rates are good. Recent IMO visual and video analyses have resulted in a complete revision of details for the swift-meteor, generally minor, near-Auriga showers, active at times between late August till October. Even so, there may be others apart from the three currently recognised. The parameters for all have been amended in our Showers List table. With New Moon occurring on Sep 5, moonlight circumstances are favourable in 2013 for these showers
: This shower is probably associated with Comet Kiess, last seen in 1911, whose period is around 2500 years, unusually long to produce what appears to be an annual shower. A bright-meteor, if badly moonlit, outburst occurred from them on 2007 September 1, when ZHRs reached ~130 (see ENBs 228
). It was predicted in advance, but other unexpected outbursts have happened too, giving estimated ZHRs of ~30-40 in 1935, 1986 and 1994. The radiant can be usefully-observed from midnight UT onwards in Britain.
September ε Perseids
: This shower seems to have been that which produced an unexpected outburst of swift, bright meteors on 2008 September 9 (see SPA ENBs 253
). However, its radiant location at the peak is actually closer to ß or δ
Persei than ε
The shower is properly observable from the UK by 22h UT, and can be watched thereafter all night.
: Past showers have typically happened only when their parent comet, 21P/Giacobini-Zinner (period around 6.6 years), was at perihelion in the autumn, as in 1998, when short-lived ZHRs of circa 700 occurred. Other returns have given rates up to storm levels (the last storm was in 1946). A largely unexpected outburst happened in 2005 (when the comet returned that July; see ENBs 184
) , so it is worth checking on in most years, just in case. Another brief outburst, reaching a ZHR of 250-300 occurred on 2011 Oct 8. The comet passed through perihelion in early 2012 and so high rates were not expected in 2012. However, a significant outburst did occur between 16h and 17h UT on Oct 8, although the exact peak ZHR was unclear.
Orionids: Linked to Comet 1P/Halley, like their May counterpart, the ? Aquarids. ZHRs are usually quite good for two to three nights centred on their peak, and may be about 25 this year from a recent IMO analysis. Activity could be still stronger, following the higher returns (ZHRs ~35-80) found from 2006-2010 inclusive, when such rates persisted for two or more nights at these levels. No repeat is expected this time. A quite strong sub-maximum has been noted occasionally around October 17-18 as well (most recently in 1998).
Maximum night, October 21, is a Sunday, but good rates should also be seen during Oct 20-23. In 2013, Full Moon occurs on Oct 18 and Last Quarter is on Oct 26. Unfortunately, after being Full the Moon moves closer to the Orionid radiant, entering Taurus early on Oct 21 and crossing into northern Orion early on Oct 23. Hence moonlight will seriously impact observations of the Orionids in 2013. Orionids are very swift meteors, with good persistent trains.
Taurids: This shower, associated with weakly-active Comet 2P/Encke (which has the shortest orbital period of any comet known (3.3 years)) is split into northern and southern components.. The two showers give low rates, but occasional fireballs spice up their prospects. Taurid meteors are typically slow moving.
The Moon is at First Quarter on Oct 11, with Full Moon occurring on Oct 18, Last Quarter on Oct 26 and New Moon on Nov 3. Thus the best conditions for Taurid observing are likely to be in the last week of October and the first week of November.
Southern Taurids: Recent IMO visual and video investigations have led to significant changes in how we think of the Southern Taurids, with amendments to the activity period and especially the maximum, which now appears to happen almost a month earlier than had long been thought, around October 10. Having said that, it is not a very sharp peak and it still makes sense to keep both Taurid showers under observation throughout October and November. Overall Taurid rates probably still peak in early November. This earlier date is however a useful reminder to be watching out for Southern Taurid meteors in early October, when the meteors then will be radiating from an area around the eastern Pisces to northern Cetus borders, rather than from well within Taurus as is the case a month later.
The Northern Taurids probably start later in October than their southern counterpart and probably continue through to early December. The IMO now list the date of maximum as Nov 12. However, as is the case for the Southern Taurids, this isn't a sharp maximum and the shower should be monitored throughout its activity period rather than simply focussing on a single night. In the period leading up to the slow-meteor Northern Taurid maximum, around late October to early November, sometimes there can be an especially fireball-rich spell (most recently in 2005 - for links see the Meteor Section Reports 2005
webpage), during one of the Taurid "swarm" returns. The "swarm" event was in 2008 produced good rates for a few days during this spell, but no unusual fireball numbers (links to reports are available on the Meteor Section Reports 2008
webpage). Another "swarm" event was predicted for 2012, but this coincided with Full Moon.
Leonids: The proximity of the shower's parent comet 55P/Tempel-Tuttle helped produce strong to storm returns during 1998-2002 inclusive, at perihelion last in 1998 (period 33 years) and there have been strong enhancements in rates due to encounters with lesser filaments in later years, most recently in 2008 and 2009. Two maximum timings have been suggested for the Leonids in 2013: one by Mikhail Maslov in WGN 35:1 (2007,p. 8) for 10h UT (ZHR ~ 15–20), the other at the nodal-crossing time close to 16h UT (ZHR perhaps 15?), both on Nov 17. Leonid are typically very swift meteors and are often trained. Unfortunately, moonlight circumstances are very unfavourable in 2013 with Full Moon also occurring on Nov 17.
Geminids: Associated with asteroid 3200 Phaethon, rather than a comet, and their meteoroids seem to be rather denser than those in most meteor showers and produce very few persistent trains. The shower is rich in bright meteors. Good rates can be seen for around two nights over their peak, but drop away very quickly after the maximum. Unlike many meteor showers, they are easily-observed throughout the night. Regular British observers often consider them the best, reliable, annual shower of the year visible here at present, though the winter weather can be trying.
The Geminid peak is due late in the night of 2013 Dec 13-14 (Fri-Sat). Unfortunately, moonlight conditions are unfavourable for the Geminids in 2013 with First Quarter occurring on Dec 9. During the night of Dec 13-14, the 89% illuminated Moon will be located in Aries and, for UK based observers, won't set until around 5am.
December Leo Minorids & Coma Berenicids: The minor Coma Berenicid shower underwent a degree of confusion in recent times, after IMO video results found apparently identically very swift, mostly faint, meteors radiating from an area about 15° west of where previous visual observations had suggested it should be, as well as from the anticipated radiant. It now seems there may be two minor showers active here, of which the December Leo Minorids is marginally the stronger, and apparently the longer-lasting. Initially thought that both peaked around December 20, the Coma shower is now believed to reach its weak maximum a few days sooner (and from a somewhat different position than earlier indicated). It may be that visual observers will struggle to identify the sources as separate, given previous apparent difficulties in this respect. With these shower only being readily observable lete in the night, moonlight will not be too much of a problem. The December Leo Minorid radiant is usefully-observable after 22:30 UT, while the Coma Berenicid radiant area is so-placed only after 01h.
Ursids: Linked with Comet 8P/Tuttle (period around 13.5 years; last at perihelion in late January 2008). Their peak rates can be quite variable, from ~10-50+, with especially good activity last in 1986. Theoretical work has suggested some enhancements occur about six years after the comet's perihelion, others near years when the comet is at perihelion (though why this latter should happen is unclear, as the comet's orbit currently passes a little outside the Earth's orbit). These theoretical considerations are only a rough guide to reality however, as enhanced ZHRs between ~25-40 were reported from 1988, 1994, 2000, 2006, 2007 and 2008, since the stronger 1986 return. With Full Moon having occurred on Dec 17, observations in the first half of the night will become increasingly moonlight-free as maximum approaches. The radiant, in Ursa Minor, is circumpolar from Britain.
Quadrantids 2014: The Quadrantid radiant, lying at Dec +50, in a rather bland area of the sky between Draco, Bootes and Ursa Major, is circumpolar for observers north of latitude 40 N. The radiant is at its lowest altitude at around 20h local time and is highest at the end of the night.
The maximum is usually rather narrow, with the predicted time of 2014 Jan 03d19h UT favouring observers in Asia. For UK based observers, the Quadrantid radiant will be fairly low in the northern sky.
The peak ZHR is usually in the region of 100, but stronger peaks have been seen occasionally (recent highs were 180 in 1992 and 160 in 2008, whereas the 2012 peak ZHR may only have been 80), and a second, lesser, maximum has been found sometimes since 2000, mainly in radio observations, about 9-12 hours after the main peak.
Moonlight will not be a problem, with New Moon having occurred on 2014 Jan 1.
The chart below shows the location of the Quadrantid radiant
Antihelion Source comments
This Source has a large, diffuse radiant area near the ecliptic, present most of the year, which tracks along slowly, roughly opposite the Sun in the sky, hence its name. Activity from it is never high, and observed rates can be virtually nonexistent for UK watchers when the radiant area is at its most southerly, from May to July. Some near-ecliptic sources are strong enough to stand out from it, such as the SDA, and possibly the CAP, in late July, while the two autumnal Taurid showers are so strong they effectively replace the ANT while they are present. Medium speed meteors, comparable in brightness range to the sporadics. You will need to extrapolate the radiant's centre for dates not listed, or see the ANT radiant drift chart in the current month's meteor activity webpage, accessible from the Meteor Section's homepage.