Meteor Activity 2013 February to 2014 JanuaryEdited by Tony Markham
Whilst moonlight circumstances were good for most of the major meteor showers during 2012, the weather tended to let down UK based observers. The good news for 2013 is that the Perseids will be better timed with respect to the Moon than in 2012 and so we can only hope for clear skies. Moonlight circumstances are also quite good for the Taurids and Ursids and, at the start of 2014, for the Quadrantids. Unfortunately, moonlight will be a serious problem in 2013 for observations of the Lyrids, Orionids, Leonids and Geminids.
With the Geminids being badly affected by moonlight, the highest observed rates in 2013 will most likely be provided by the Perseids in August.
Virginids / Spring Antihelion SourceAfter the Quadrantids of January, night time meteor rates are rather low for northern hemisphere observers. However, from mid February to early May there are a number of minor showers with radiants close to the ecliptic. Older sources collectively refer to these as the Virginids, whilst more recently lists treat them (and later showers such as the Capricornids and Piscids) as being part of an "Antihelion source" that is assumed to be active throughout the year from an area of sky located about 180 degrees from the Sun. Minor showers historically grouped together as the "Virginids" have included the Delta Leonids (max Feb 26), the Alpha Virginids (max Apr 11-12) and the Gamma Virginids (max Apr 14). Peak rates from this collection of minor showers generally occur in early April.
New Moon in 2013 occurs on Mar 11 and Apr 10.
Lyrids max Apr 22d11h UTChart. Lyrid activity can be seen from Apr 18-25 each year. For observers at northern latitudes, the Lyrid radiant is above the horizon all night. As for many of the major meteor showers, observed rates pick up as the radiant altitude increases during the night, so meteor watches after midnight are the most productive. The Lyrids are the main night time meteor shower of the spring months for northern hemisphere observers. Although they don't usually produce observed rates comparable with major showers that occur later in the year, the Lyrids do stand out relative to the low background activity of the spring months. Some intense but brief Lyrid outbursts have occasionally been seen, such as in 1982.
Unfortunately, Full Moon in 2013 occurs on Apr 25 and, although the Lyrid peak occurs three days before this, the 83% illuminated waxing gibbous Moon will be on the Leo/Sextans border on the morning of April 22 and, for UK based observers, will not set until morning twilight is underway. Hence moonlight will seriously hinder Lyrid observations this year.
Eta Aquarids max May 4-5This shower, resulting from the Earth's post-perihelion encounter with the meteoroid stream of comet Halley, is active from late April to mid May and produces higher peak ZHR values than do the Lyrids. However, while easy to observe from the southern hemisphere and from the tropics, for observers in northern Europe dawn is approaching before the radiant reaches a reasonable altitude. Thus observers at northern latitudes can only expect low observed rates.
In 2013, the Eta Aquarid peak occurs between Last Quarter and New Moon. On the morning of May 5, the crescent Moon will be 23% illuminated, located on the Aquarius/Pisces border (only about 5 degrees from the shower radiant) and, from the UK, rising around 40 mins after the Eta Aquarid radiant. The radiant is in northern Aquarius, at RA 22h20m, Dec -01.
Daytime showersFor observers at northern latitudes the Eta Aquarids are almost a daytime-only shower. However, active throughout May and June are several showers whose radiants are only above the horizon during daylight hours (although in a few cases, some activity may be detectable late in the night by observers in tropical latitudes). Consequently observation of these showers is limited to radio methods. ZHR and radiant information is generally poorly known. The most active of these showers appear to be the May Arietids (max May 16), the Omicron Cetids (max May 20), the Arietids (max Jun 7), The Zeta Perseids (max Jun 9) and the Beta Taurids (max Jun 28).
June Bootids max Jun 23-24?This shower produced an unexpected outburst in 1998, with a broad peak during June 27-28. Another outburst was seen on 2004 June 23. Although several outbursts from this shower were seen in the early 20th century, these latest outbursts were unexpected as the Earth now passes some distance from the orbit of the particles which produced the earlier outbursts. The parent comet 7P/Pons-Winnecke was at perihelion on 2008 Sep 26, but there is no evidence that recent outbursts have been related to the position of the comet. It is worthwhile monitoring this shower's activity however in case further outbursts occur. There is some uncertainty as to the current location of the shower radiant, with recent reports merely describing the activity as originating from "northern Bootes".
In 2013, Full Moon occurs on June 23 with the Moon in Sagittarius - well away from the June Bootid radiant. During the night of June 27-28, the waning gibbous Moon will be 73% illuminated and near the Aquarius/Pisces border. All-night twilight may also be a problem for observers at more northerly latitudes
July Minor ShowersNight-time sporadic activity picks up in July. Among the minor showers sometimes listed are the Alpha Cygnids, which are active throughout the month and into early August (radiant 21h00m, +48) and the Lacertids, which are active later in the month (radiant 22h05m, +37). Neither shower seems to have any clearly defined maxima and it is possible that many of the meteors assigned to the showers have merely been chance lining-ups of sporadic meteors.
New Moon in 2013 occurs on July 8, with Full Moon occurring on July 22.
Aquarid-Capricornid complex / Summer Antihelion SourceChart. This Aquarid-Capricornid group of showers includes the Delta Aquarids-S (max July 28-29), the Piscis Australids (max July 31), the Alpha Capricornids (max Aug 2), the Delta Aquarids-N (max Aug 5-9) and the Iota Aquarids-S (max Aug 6-7). Other than for the Delta Aquarids-S, the peak ZHRs are all below 10 per hour. The Alpha Capricornids have been noted for producing a number of slow moving flaring fireballs. Rather confusingly some sources refer to the Alpha Capricornids as the Capricornids, whilst others use the term Capricornids to describe a minor shower peaking around July 25 !
The proximity of the radiants to each other, together with their motion from night to night means that visual observers must take great care to distinguish between the individual showers. For this reason, the above showers, with the exception of the Delta Aquarid-S and Alpha Capricornids, are often now merely grouped together as part of the "Summer Antihelion Source".
With the Last Quarter Moon in 2013 occurring on July 29 and New Moon on Aug 6, observations of the Delta Aquarid-S peak will suffer some moonlight interference with the Moon being located near the Aquarius/Pisces border, but the other shower peaks will be affected less.
Perseids max Aug 12d18h UTChart. Despite not producing peak rates as high as those of the Geminids, the Perseid meteor shower remains the favourite for most observers. This is because, in addition to being rich in bright and trained meteors, it also occurs during summer in the northern hemisphere as opposed to the cold nights of December for the Geminids.
Perseid activity can be seen from the last week of July through to the third week of August. The highest observed rates on any given night are likely to be seen when the radiant is highest in the sky late in the night. The more detailed analyses of recent decades have also shown that there is often more than one Perseid peak, the supplementary peaks being shifted several hours away from the main peak and probably associated with dust trails left behind by specific perihelion passages of the parent comet. However, there are no predictions for additional Perseid peaks in 2013.
For UK based observers, the best observed rates are likely to be seen late in the night of Aug 12-13 (Mon-Tue), although high rates should also be seen during Aug 11-12 and to a lesser extent during Aug 13-14. Moonlight conditions in 2013 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.
August Minor ShowersSporadic activity is quite high in August and numerous minor showers have been reported as being active. Many of them are probably spurious, with some of their supposed members being misidentified Perseids and late members of the Aquarid/Capricornid complex.
The more reliable showers include the Alpha Aurigids, which reach maximum late in the month (radiant RA 04h56m , Dec +43), and the Kappa Cygnids which reach maximum on Aug 20 (radiant 19h20m, +55) and often produce fireballs. Some sources also list an Iota Aquarid-N maximum on Aug 20 and a second Kappa Cygnid maximum on Aug 26.
Full Moon in 2013 occurs on Aug 21 and so moonlight is likely to have a serious impact on observations of the above showers.
Minor Showers in September / early Autumn Antihelion SourceSporadic activity is also high in September and, again, numerous minor showers have been reported, although not as many as for August, probably because less observers are usually active. Be aware that in many cases the names allocated to these minor showers varies from one source to the next ! The more reliable minor showers include the Alpha Aurigids (continuing from August), the Beta Cassiopeids (max Sep 1-6, radiant 00h05m, +63), the Epsilon Perseids (max Sep 3-7, radiant 04h10m, +37), the Delta Aurigids (max Sep 8, radiant 04h00h, Dec +47) and the Piscids (max Sep 8-9, radiant 00h36m, +07 ; max Sep 21, radiant 00h24m, +00).
More recent sources usually include the Piscids as part of the "Antihelion Source" (whereas later autumn ecliptic based radiants are allocated to the Taurid complex)
New Moon in 2013 occurs on Sep 5, favourable for the showers listed above, with Full Moon occurring on Sep 19.
Draconids (Giacobinids) max Oct 8-921P/Giacobini-Zinner, the parent comet of this shower, passed through perihelion in Feb 2012. Observations of the Earth's closest passage to the comet's orbit at around Oct 8 2011 was seriously impacted by a bright Moon, but a short lived outburst to a ZHR of 250-300 was seen.
High Draconid rates were not expected in 2012. However, the limited number of radio, radar and visual observations that were made indicated that a significant outburst occurred at around 16h-17h UT on Oct 8. Peak ZHR values are uncertain, due to the poor observing conditions of the visual observers, but may have exceeded 100. Once again, nothing exceptional is expected for 2013, but it would be worthwhile watching out for activity just in case.
The radiant, at RA 17h23m, Dec +57, lies near the head of Draco and is quite high in the sky for observers at northern latitudes at the start of the night. Draconid meteors are relatively slow moving.
In 2013, the Moon will be a 16% illuminated crescent in Scorpius on the evening of Oct 8, setting at the start of the night for UK based observers.
Orionids Max Oct 20-23Chart. Orionid activity lasts from Oct 14-31, with a broad maximum occurring between Oct 20 and Oct 23 - however, even within this period there will proably be several peaks and troughs in the activity levels. The Orionids, which are the result of the Earth's per-perihelion encounter with the meteoroid stream of comet Halley, sometimes brings surprises such as the unusually high rates seen during the night of 2006 Oct 21-22. There were also indications of enhanced rates in 2008 and 2009 and
The radiant position at maximum is RA 06h24m , Dec +15 (on the border of Gemini and Orion) but actually appears quite diffuse since it consists of a number of sub-centres, as shown by the chart, whose combined activity can give the impression of the radiant remaining almost stationary for several days. The Orionid radiant does not rise until mid evening and is highest in the sky late in the night.
In 2013, Full Moon occurs on Oct 18 and Last Quarter in 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.
Taurids Max early NovChart. Taurid activity lasts throughout October and November. Although individual dates of maxima are often quoted for the northern and southern Taurids, the shower does not have sharp peaks in the same sense as seen in showers such as the Perseids or Leonids and it makes more sense to treat the shower as showing a broad maximum in early November. Observed rates are far from spectacular, but some observers report that the shower produces a good percentage of fireballs. Indeed a good number of bright Taurids were reported in 2005 and analyses by David Asher have supported the idea of a Taurid 'swarm' that the Earth encounters every few years. Results from 2008 showed some enhancement in Taurid rates, but few extra fireballs. The swarm was predicted to encounter the Earth again in late October 2012, but observations of possible activity were badly affected by moonlight.
Some Taurid activity will also be visible during the Orionid watches of October and the Leonid watches of November. The Taurid radiants are highest at around the middle of the night.
With New Moon occurring on Nov 3, the broad Taurid peak will start moonlight free, but will suffer some evening moonlight interference in its later stages.
Leonids max Nov 17-18
Chart. Leonid activity last from Nov 14-20 each year. The Leonid radiant rises in the late evening and is highest in the sky around dawn. The Leonids produced storm level activity for observers at favoured locations in 1999, 2001 and 2002.
It had been assumed that we had encountered all of the significant Leonid filaments. However, in 2008 the Earth passed close to a filament of material ejected at the 1466 return of the parent comet, resulting in rates being enhanced to around normal Perseid levels. A further close approach to this filament in 2009 resulted in similar rates during 20h-21h UT on Nov 17. Observing conditions were fairly unfavourable in 2010, but data reported did indicate a ZHR over 20 - and so well above the rates usually quoted for years between perihelion returns of the parent comet.
Unfortunately, moonlight circumstances are very unfavourable in 2013 with Full Moon occurring on Nov 17
Geminids max Dec 14d06h UTChart. Although the Geminids were overshadowed by the enhanced Perseid activity of the early 1990s and the enhanced Leonid activity of 1998-2002, the Geminids are the shower that produce the highest reliable rates year on year and only lose out in popularity to the Perseids due to the colder December nights.
Geminid activity can be seen from Dec 7-16. Results from recent years have shown the peak ZHR to be over 100 and to remain above 70 per hour for about 24 hours - and the shower's profile is evolving from year to year. The Geminids are typically rich in bright meteors, but produce few trained meteors. There seems to be a tendency for fainter telescopic meteors to peak earlier than brighter meteors. The radiant is highest at about 02h local time and for observers at northern temperate latitudes is above the horizon all night.
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.
Ursids max Dec 22-23Ursid activity lasts from approx Dec 17-25, with the radiant, at RA 14h28m, Dec +78, being highest late in the night and circumpolar for most northern hemisphere observers. High rates were recorded from this shower in 1945, 1982 ,1986, 2000, 2004 and 2006. It is suspected that other such peaks may have been missed due to lack of observations.
With Full Moon in 2013 occurring on Dec 17 and Last Quarter on Dec 25, there will be scope for observing the Ursid peak during moon-free evening skies, before conditions worsen after moonrise.
Quadrantids 2014 max Jan 03d19h UTChart. 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 for 2014 favouring observers in Asia. For UK based observers, the Quadrantid radiant will be low in the northern sky.
Peak rates vary from year to year. The ZHR for the 2012 peak only seemed to reach around 80 whereas the 2009 peak was broader than usual with the ZHR being above 100 for nearly 12 hours.
Moonlight will not be a problem, with New Moon having occurred on Jan 1.
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