October to December

New Moon in these three months falls such that observations of 13 of the 15 meteor showers with potential maxima can receive some useful coverage at least. The two which lose out as too near full Moon are the chi-Orionids (maximum on December 1) and the Ursids (peak due on December 22, most likely near 7h UT, but possibly up to two hours or so later).

Draconids

Active       : October 6-10;
Maximum      : October 8, 10h UT, (sol = 195.4°, but see below);
ZHR          = periodic, up to storm levels;
Radiant      : alpha = 262°, delta = +54°;
Radiant drift: negligible;
V            = 20 km/s;
r            = 2.6;
TFC          : alpha = 290°, delta = +65° and
               alpha = 288°, delta = +39° (beta>30° N).

Figure 13: Radiant position of the Draconids

The Draconids are primarily a periodic shower which produced spectacular, brief, meteor storms twice last century, in 1933 and 1946, and lower rates in several other years (ZHRs 20-500+), most recently in 1998 (when EZHRs briefly reached 700). Most detected showers were in years when the stream's parent comet, 21P/Giacobini-Zinner, returned to perihelion, as last in 1998 November. The next return of the comet is in mid 2005. The 1998 outburst happened at sol = 195.07°, equivalent to 2004 October 8, 2h 10m UT, although the nodal crossing time used above, close to sol = 195.4°, may be more generally applicable. In 1999 an unexpected minor visual-radio outburst (ZHRs 10-20) occurred over the Far East between sol = 195.63°-195.76°. A repeat at this time would be on 2004 October 8, 15h 40m - 18h 50m UT. The radiant is circumpolar from many northern hemisphere locations, but is higher in the pre-midnight and near-dawn hours in early October. The waning crescent Moon makes this a good year to see what the shower yields - even if this is nothing detectable. Draconid meteors are exceptionally slow-moving, a characteristic which helps separate genuine shower meteors from sporadics accidentally lining up with the radiant.

epsilon-Geminids

Active       : October 14-27;
Maximum      : October 18, (sol = 205°);
ZHR          = 2;
Radiant      : alpha = 102°, delta = +27°;
Radiant drift: see Table 6;
V            = 70 km/s;
r            = 3.0;
TFC          : alpha = 90°, delta = +20° and
               alpha = 125°, delta = +20° (beta>20° S).

A weak minor shower with characteristics and activity nearly coincident with the Orionids, so great care must be taken to separate the two sources by instrumental techniques - especially video or telescopic work - or visual plotting. The early-setting waxing crescent Moon on October 18 presents an excellent opportunity to obtain more data on them from either hemisphere, although northern observers have an advantage, and can usefully access the radiant from about midnight onwards.

Orionids

Active       : October 2 - November 7;
Maximum      : October 21 (sol = 208°);
ZHR          = 23;
Radiant      : alpha = 95°, delta = +16°;
Radiant drift: see Table 6;
V            = 66 km/s;
r            = 2.5;
TFC          : alpha = 100°, delta = +39° and
               alpha = 75°, delta = +24° (beta>40° N); or
               alpha = 80°, delta = +1&#176 and
               alpha = 117°, delta = +1° (beta<40° N).

Figure 14: Radiant position and drift of the Orionids and epsilon-Geminids

October's waxing gibbous Moon favours the Orionids on October 20/21, as it will be setting - or indeed have long set for the northern hemisphere - by the time the radiant is at a useful elevation (around local midnight in either hemisphere, somewhat before in the north). Most of the globe can enjoy the shower, as the radiant is quite near the celestial equator. Audrius Dubietis carried out an analysis of the shower in IMO data from 1984-2001 in early 2003, which has allowed some minor modifications to the peak ZHR and r parameters above. Both these aspects were also shown to vary somewhat from year to year, the maximum mean ZHR especially ranging from 14-31 during the last two decades. In addition, a suspected 12-year periodicity in higher returns found earlier in the 20th century appears to have been partly confirmed, which may mean stronger returns in 2008-2010. The Orionids were always noted for having several lesser maxima other than the main one above, helping activity sometimes to remain roughly constant for several consecutive nights centred on this peak. In 1993 and 1998, a submaximum about as strong as the normal peak was detected on October 17/18 from Europe, for instance. All observers should be aware of these possibilities, as observing circumstances are very favourable for covering October 17/18 in dark skies this year. Several subradiants have been reported in the past, but recent video work suggests the radiant is far less complex; photographic, telescopic and video work to confirm this would be useful, as visual observers have clearly had problems with this shower's radiant determination before.

Taurids

Southern Taurids

Active       : October 1-November 25;
Maximum      : November 5 (sol = 223°);
ZHR          = 5;
Radiant      : alpha = 052°, delta = +13°;
Radiant drift: see Table 3;
V            = 27 km/s;
r            = 2.3;
TFC          : Choose fields on the ecliptic and about 10° E or W of the
               radiants (beta>40° S).

Northern Taurids

Active       : October 1-November 25;
Maximum      : November 12 (sol = 230°);
ZHR          = 5;
Radiant      : alpha = 058°, delta = +22°;
Radiant drift: see Table 3;
V            = 29 km/s;
r            = 2.3;
TFC          : as Southern Taurids.

Figure 15: Radiant position and drift of the Northern and Southern Taurids

These two streams form part of the complex associated with Comet 2P/Encke. Defining their radiants is best achieved by careful visual or telescopic plotting, photography or video work, since they are large and diffuse. They are currently being studied using IMO data by Mihaela Triglav. The brightness and relative slowness of many shower meteors makes them ideal targets for photography, while these factors coupled with low, steady, combined Taurid rates makes them excellent targets for newcomers to practice their plotting techniques on. The activity of both streams produces an apparently plateau-like maximum for about ten days in early November, and the showers have a reputation for producing some excellently bright fireballs at times, although seemingly not in every year. David Asher has indicated that increased Taurid fireball rates may result from a "swarm" of larger particles within the Taurid stream complex, and he suggested such "swarm" returns might happen in 1995 and 1998 most recently. In 1995, an impressive crop of bright Taurids occurred between late October to mid November, while in 1998, Taurid ZHRs reached levels comparable to the usual maximum rates in late October, together with an increased flux of brighter Taurids generally. The next potential October-November "swarm" return is not predicted until 2005, but we cannot be sure how correct this is as yet. Unfortunately, full Moon ruins this period in 2004, but this does mean a last quarter waning to new Moon for the regular early November maxima.

The near-ecliptic radiants for both shower branches mean all meteoricists can observe the streams. Northern hemisphere observers are somewhat better-placed, as here suitable radiant zenith distances persist for much of the late autumnal nights. Even in the southern hemisphere, a good 3-5 hours' watching around local midnight is possible with Taurus well above the horizon, however.

Leonids

Active       : November 14-21;
Maximum      : November 17, 8h 25mUT (sol = 235.27°);
ZHR          = 10-50+
Radiant      : alpha = 153°, delta = +22°;
Radiant drift: see Table 6;
V            = 71 km/s;
r            = 2.9;
TFC          : alpha = 140°, delta = +35° and
               alpha = 129°, delta = +6° (beta>35° N); or
               alpha = 156°, delta = -3° and
               alpha = 129°, delta = +6° (beta<35° N);
PFC          : before 00h local time alpha = 120°, delta = +40° (beta>40° N);
               before 04h local time alpha = 120°, delta = +20° (beta>0° N);
           and after  04h local time alpha = 160°, delta = 0°   (beta>0° N);
               before 04h local time alpha = 120°, delta = +10° (beta<0° N)
           and after  04h local time alpha = 160°, delta = -10° (beta<0° N).

Figure 16: Radiant position and drift of the Leonids

In theory, the ending of the strong to storm Leonid returns between 1998-2002 associated with particles accompanying the shower's parent comet, 55P/Tempel-Tuttle, which had returned to its perihelion in 1998, should mean 2004 will see a continuing decline in activity back towards its earlier ZHRs of 10-15. Certainly, no enhanced activity is predicted, although as meteor enthusiasts know well, surprises can occur from even the best-known showers on occasion! Observers should be alert to covering whatever the shower produces, as following the post-storm phases after this best-ever observed run of storm returns is as vital to our understanding of the stream as seeing the storms themselves. The Leonid radiant rises usefully only around local midnight (or indeed afterwards south of the equator), splendid news, as the waxing crescent Moon will have set long before this time on November 16/17. If the peak occurs close to the nodal crossing time above, it will favour sites across the Americas, but other peak times cannot be excluded, and observers should be watching as often as conditions allow throughout the shower, in case something unexpected happens. All observing techniques can be usefully employed.

alpha-Monocerotids

Active       : November 15-25;
Maximum      : November 21, 8h 45m UT (sol = 239.32°);
ZHR          = variable, usually around 5 but may produce outbursts to around 400+;
Radiant      : alpha = 117°, delta = +1°;
Radiant drift: see Table 6;
V            = 65 km/s;
r            = 2.4;
TFC          : alpha = 115°, delta = +23° and
               alpha = 129°, delta = +20° (beta>20° N); or
               alpha = 110°, delta = -27° and
               alpha = 98°, delta = +6° (beta<20° N);

Figure 17: Radiant position and drift of the alpha-Monocerotids

Another late-year shower capable of producing surprises, the alpha-Monocerotids gave their most recent brief outburst in 1995 (the top EZHR, 420, lasted just five minutes; the entire outburst 30 minutes). Many observers across Europe witnessed it, and we have been able to completely update the known shower parameters as a result. Whether this indicates the proposed ten-year periodicity in such returns is real or not, only the future will tell (next year!), so all observers should continue to monitor this source closely. The waxing gibbous Moon on November 20/21 will have set by 1h-2h local time across much of the world, so observing is eminently practical, because the radiant is well on view from either hemisphere after about 23h local time. The expected peak falls especially well for sites in the Americas, except for the more easterly parts of South America.

Phoenicids

Active       : November 28-December 9;
Maximum      : December 6, 2h 35mUT (sol = 254.25°);
ZHR          = variable, usually 3 or less, may reach 100;
Radiant      : alpha = 018°, delta = -53°;
Radiant drift: see Table 6;
V            = 18 km/s;
r            = 2.8;
TFC          : alpha = 040°, delta = -39° and
               alpha = 065°, delta = -62° (beta<10° N).

Figure 18: Radiant position and drift of the Phoenicids

Only one impressive Phoenicid return has so far been reported, that of its discovery in 1956, when the ZHR was 100. Three other potential bursts of lower activity have been reported, but never by more than one observer, under uncertain circumstances. Reliable IMO data shows recent activity to be virtually nonexistent. This may be a periodic shower however, and more observations of it are needed by all methods. Radio workers may find difficulties, as radar echoes from the 1956 event were only 30 per hour, perhaps because these low-velocity meteors produce too little radio-reflecting ionization. Observing conditions for all southern hemisphere watchers are moderate, with last quarter Moon rising only around 1h local time on December 5/6, while the radiant culminates at dusk, remaining well on view for most of the night.

Puppid-Velids

Active       : December 1-December 15;
Maximum      : December 6 (sol = 255°);
ZHR          = about 10;
Radiant      : alpha = 123°, delta = -45°;
Radiant drift: see Table 3;
V            = 40 km/s;
r            = 2.9;
TFC          : alpha = 090° to 150°, delta = -20° to -60°;
               choose pairs of fields separated by about 30° in alpha, moving
               eastwards as the shower progresses (beta<10° N).

This is a very complex system of poorly-studied showers, visible chiefly to those south of the equator. Up to ten sub-streams have been identified, with radiants so tightly clustered, visual observing cannot readily separate them. Photographic, video or telescopic work would thus be sensible, or very careful visual plotting. The activity is so badly known, we can only be reasonably sure that the highest rates occur in early to mid December, coincident with a waning Moon this year. Some of these showers may be visible from late October to late January. Most Puppid-Velid meteors are quite faint, but occasional bright fireballs, notably around the suggested maximum here, have been reported previously. The radiant area is on-view all night, but is highest towards dawn.

Monocerotids

Active       : November 27-December 17;
Maximum      : December 8 (sol = 257°);
ZHR          = 3;
Radiant      : alpha = 100°, delta = +8°;
Radiant drift: see Table 6;
V            = 42 km/s;
r            = 3.0;
TFC          : alpha = 088°, delta = +20° and
               alpha = 135°, delta = +48° (beta>40° N); or
               alpha = 120°, delta = -03° and
               alpha = 84°, delta = +10° (beta<40° N);

Only low visual rates are likely from this minor source, making accurate visual plotting, telescopic or video work essential, particularly because the meteors are normally faint. The shower's details, even including its radiant position, are rather uncertain. Recent IMO data show only weak signs of a maximum as indicated above. Telescopic results suggest a later maximum, around December 16 (sol 264°) from a radiant at alpha = 117°, delta = +20°. This is a reasonable year for making observations, as the waning crescent Moon rises by 2h-3h local time for all observers on December 8, while the radiant is on-show virtually all night, culminating about 1h 30m local time.

sigma-Hydrids

Active       : December 03-15;
Maximum      : December 11 (sol = 260°);
ZHR          = 2;
Radiant      : alpha=127°, delta=+02°;
Radiant drift: see Table 6;
V            = 58 km/s;
r            = 3.0;
TFC          : alpha=095°, delta=00° and alpha=160°, delta=00°
               (all sites, after midnight only).

Figure 19: Radiant position and drift of the sigma-Hydrids

Although first detected in the 1960s by photography, sigma-Hydrids are typically swift and faint, and rates are generally very low, close to the visual detection threshold. Since their radiant, a little over 10° east of the star Procyon (alpha Canis Minoris), is near the equator, all observers can cover this shower. The radiant rises in the late evening hours, but is best viewed after local midnight. New Moon creates a perfect viewing opportunity for the peak date given above this year. Recent data indicates the maximum may happen up to six days earlier than this, which would be much less favourable for Moon-free watching. The shower would benefit from visual plotting, telescopic or video work to pin it down more accurately.

Geminids

Active       : December 7-17;
Maximum      : December 13, 22h 20m UT (sol = 262.2°) +/- 2.3h;
ZHR          = 120;
Radiant      : alpha = 112°, delta = +33°;
Radiant drift: see Table 6;
V            = 35 km/s;
r            = 2.6;
TFC          : alpha = 87°, delta = +20° and
               alpha = 135°, delta = +49°; before 23h local time,
               alpha = 87°, delta = +20° and
               alpha = 129°, delta = +20° after  23h local time (beta>40° N);
               alpha = 120°, delta = -3° and
               alpha = 84°, delta = +10° (beta<20° N);
PFC          : alpha = 150°, delta = +20° and
               alpha = 60°, delta = +40° (beta>20° N);
           and alpha = 135°, delta = -5° and
               alpha = 80°, delta = 0° (beta<20° N)

Figure 20: Radiant position and drift of the Geminids and Monocerotids

One of the finest annual showers presently observable. This year, new Moon on December 12 gives perfect observing conditions across the expected maximum on December 13/14. The Geminid radiant culminates around 2h local time. Well north of the equator, the radiant rises around sunset, and is at a usable elevation from the local evening hours onwards. In the southern hemisphere, the radiant appears only around local midnight or so. Even here, this is a splendid shower of often bright, medium-speed meteors, a rewarding sight for all watchers. The peak has shown slight signs of variability in its maximum rates and peak timing in recent years, with the six most reliably observed maxima over the past 15 years having all occurred within 2h 20m of the time above. The main predicted timing favours European and North African locations eastwards to central Russian and Chinese longitudes. An earlier or later timing would extend this best-visible zone some way eastwards or westwards respectively. Some mass-sorting within the stream means the fainter telescopic meteors should be most abundant almost 1° of solar longitude (about one day) ahead of the visual maximum, with telescopic results indicating these meteors radiate from an elongated region, perhaps with three sub-centers. Further results on this topic would be useful, but all methods can be employed to observe the shower.

Coma Berenicids

Active       : December 12 - January 23;
Maximum      : December 19, (sol = 268°);
ZHR          = 5;
Radiant      : alpha = 175°, delta = +25°;
Radiant drift: see Table 6;
V            = 65 km/s;
r            = 3.0;
TFC          : alpha = 180°, delta = +50° and
               alpha = 165°, delta = +20° before 03h local time; or
               alpha = 195°, delta = +10° and
               alpha = 200°, delta = +45° after 03h local time (beta>20° N).

Figure 21: Radiant position and drift of the Coma Berenicids

A weak minor shower that is usually observed only during the Geminid and Quadrantid epochs, but which needs more coverage at other times too, especially to better-define its maximum. The shower is almost unobservable from the southern hemisphere, so northern watchers must brave the winter cold to improve our knowledge of it. The radiant is at a useful elevation from local midnight onwards, conveniently after waxing gibbous moonset in 2004.