No matter where you live, the first half of December provides some of the best meteor activity of the year. In the northern hemisphere the sporadic rates are still strong plus you can also count on strong activity from the Geminids, which peak on December 13. There are also several minor radiants that add a few meteors each hour. All of these centers of activity are located high in the sky during the early morning hours this time of year. Much of the activity mentioned above can also be seen from the southern hemisphere. While the sporadic rates are not as strong as those seen from the north, they are stronger than the previous months and heading for a maximum in February. The warm, but short summer nights south of the equator make for some great viewing as long as the moon does not interfere.
During this period the moon reaches its new phase on Tuesday December 3rd. At this time the moon will lie near the sun and will be invisible at night. This weekend the very thin waning crescent moon will rise shortly before dawn and will not cause any interference to meteor observers. The estimated total hourly meteor rates for evening observers this week is near 5 for observers located in the northern hemisphere and 4 for those viewing south of the equator. For morning observers the estimated total hourly rates should be near 22 as seen from mid-northern latitudes and near 16 for observers viewing from tropical southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brightest meteors will be visible from such locations.
The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning November 30/December 1. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.
The following sources of meteoric activity are expected to be active this week:
The December Phoenicids (PHO) are a periodic shower that rarely produces noticeable activity. The only impressive display produced by this shower occurred in 1956 when ZHR’s were near 100. Peak activity occurs on December 6. Little activity is expected away from the peak night. The radiant is currently located at 00:46 (016) -53. This position lies in eastern Phoenix, five degrees northwest of the first magnitude star Archernar (Alpha Eridani). These meteors are best seen near 2000 (8pm) local standard time (LST), when the radiant lies highest above the horizon in a dark sky. Due to the southerly declination of the radiant, this shower is not visible north of the northern tropical areas. The deep southern hemisphere has the best chance of seeing any activity. At 22 km/sec. the Phoenicids produce very slow meteors.
The December Phi Cassiopeiids (DPC) were discovered by Peter Jenniskens and are weakly active from November 26 through December 5th. Maximum activity occurs on December 1st when the radiant is located at 01:33 (023) +53. This area of the sky is located in southern Cassiopeia, 3 degrees southeast of the faint star known as Theta Cassiopeiae. The radiant is best placed near 2100 (9 pm) local standard time (LST), when it lies highest above the horizon. Rates should be near less than 1 per hour no matter your location.
The Northern Taurids (NTA) are active from a large radiant centered at 05:00 (075) +25, which lies in northern Taurus, directly between the bright stars Aldebaran (Alpha Tauri) and El Nath (Beta Tauri). The radiant is best placed near midnight LST, when it lies highest above the horizon. Rates should be near 2 per hour as seen from the northern hemisphere and 1 as seen from south of the equator. With an entry velocity of 29 km/sec., most activity from this radiant would be of medium-slow speed.
The November Orionids (NOO) are active from a radiant currently located at 06:08 (092) +15. This position lies in northeastern Orion near the faint star known as Nu Orionis. These meteors are best seen near 0100 LST when the radiant lies highest above the horizon. Current rates should be near 3 per hour no matter your location. With an entry velocity of 44 km/sec., most activity from this radiant would be of medium speed.
The Monocerotids (MON) are active from November 27th through December 17th. Peak activity occurs on December 9th. The radiant is currently located at 06:20 (095) +09. This position lies on the Monoceros/Orion border, 5 degrees east of the first magnitude orange star known Betelgeuse (Alpha Orionis) Current rates should be less one per hour this weekend increasing to near 1 per hour later in the period. The Monocerotids are best seen near 0100 LST when the radiant lies highest above the horizon. At 41 km/sec. the Monocerotids produce mostly meteors of medium velocity.
Geminid (GEM) activity begins this week from a radiant located near 06:55 (104) +34. This position lies in northern Gemini, near the fourth magnitude star Theta Geminorum. Expected rates this week would only be near one per hour as maximum is still 2 weeks away. Although Geminid meteors can be seen all night long, they are best seen near 0200 LST when the radiant lies highest above the horizon. This shower peaks on the night of December 12/13, when rates can surpass 60 shower members per hour in moonless skies. Unfortunately this year there will be a bright moon and observers will be limited to viewing just before dawn, when the moon has set. Geminid activity can be seen from the southern hemisphere but at much reduced rate. As seen from south of the equator, Geminid activity could only be seen for a few hours before and after 0200 LST. At 35 km/sec. the Geminids produce mostly meteors of medium velocity.
The Puppid-Velids (PUP) are a vast complex of weak radiants located in the constellations of Puppis and Vela. Visual plots and photographic studies have revealed many radiants in this area during November and December. The combined strength of these radiants can produce a ZHR of ten. Actual hourly rates will be much less unless you happen to be observing from the deep Southern Hemisphere. Activity from this source begins around December 1st. The center of this activity is currently located at 08:00 (120) -45. This position lies in western Vela, two degrees north of the second magnitude star Gamma Velorum. Peak rates occur near December 7. These meteors are best seen near 0300 LST when the radiant lies highest above the horizon in a dark sky. Observers located in the Southern Hemisphere have an advantage viewing this shower as the radiant will rise higher into their sky allowing more activity to be seen. Since the radiant lies low in the south for most northern hemisphere observers, meteors seen from north of the equator tend to be long in length and long-lasting. At 40 km/sec. the Puppid-Velids produce meteors of average velocity.
The Sigma Hydrids (HYD) are active from November 26 through December 21, with maximum activity occurring on December 6. The radiant is currently located at 08:00 (120) +04, which places it in eastern Canis Minor, 5 degrees southeast of the brilliant zero magnitude star known as Procyon (Alpha Canis Minoris). These meteors are best seen near 0300 LST when the radiant lies highest above the horizon. Current rates should be near 3 per hour no matter your location. With an entry velocity of 62 km/sec., most activity from this radiant would be of swift speed.
Activity from the December Leonis Minorids (DLM) begins next week from a radiant located at 09:20 (140) +36. This position lies in extreme eastern Lynx, just north of the fourth magnitude star known as Alpha Lyncis. These meteors are best seen near 0400 LST when the radiant lies highest above the horizon. This shower peaks on December 17th so current rates would be near less than one per hour no matter your location. At 64 km/sec. the December Leonis Minorids produce mostly swift meteors.
The Psi Ursa Majorids (PSU) were discovered by observers in Japan using data from SonotaCo. This shower is active from November 29-December 13 with maximum activity occurring on December 5. At maximum the radiant is located at 11:07 (167) +43. This position lies in southern Ursa Major, one degree south of the third magnitude star Psi Ursae Majoris. This area of the sky is best placed during the last hour before dawn, when it lies highest above the horizon in a dark sky. Current rates would most likely be less than one per hour and may reach 1 per hour at maximum. Observers south of the equator would see rates less than 1 per hour due to the lower radiant elevation. At 61km/sec., the average Psi Ursa Majorid meteor would be swift.
The December Kappa Draconids (KDR) are another shower discovered in Japan by observers using data from SonotaCo. This shower is active from November 30-December 6 with maximum activity occurring on December 3rd. On the night of maximum the radiant will be located at 12:24 (186) +70. This position lies in extreme western Draco, close to the faint star Kappa Draconis. While the radiant lies above the horizon all night for most of the northern hemisphere, it is best placed during the last hour before dawn, when it lies highest above the horizon in a dark sky. Rates could reach 3 per hour on the morning of the 3rd. Away from that morning I would expect hourly rates of less than 1. Due to the high northerly declination of the radiant these meteors are not visible from most of the southern hemisphere. At 43km/sec., the average December Kappa Draconid meteor would be of medium velocity.
The last of the November Iota Draconids (NID) may be seen this weekend. This weak display is active from November 22 through December 1, with maximum activity occurring on November 26. The radiant is currently located at 12:40 (190) +64. This area of the sky lies in western Draco, 6 degrees south of the fourth magnitude star Kappa Draconis. The radiant is best placed during the last hour before dawn, when it lies highest above the horizon in a dark sky. Current rates would be less than one shower member per hour, no matter your location. Due to the high northerly declination of the radiant, observers south of the equator are at a distinct disadvantage in trying to see these meteors. Only southern equatorial regions would have any chance of seeing activity from this source. Meteors from the November Iota Draconids strike the atmosphere at 44km/sec., which would produce meteors of medium velocity.
Lastly, the December Alpha Draconids (DAD) begin to appear late in this period, around December 5th. They are predicted to peak on December 8th from a radiant located at 13:01 (210) +60. This position actually lies in northeastern Ursa Major, 4 degrees northeast of the second magnitude star known as Alioth (Epsilon Ursae Majoris). These meteors are best seen during the last dark hour before dawn, when the radiant lies highest above the horizon in a dark sky. This shower is not well seen from the southern hemisphere. Current hourly rates would probably be less than one no matter your location. At 43 km/sec. the Alpha Draconids produce mostly medium speed meteors. This is another shower discovered by Japanese observers using data from SonotaCo.
As seen from the mid-northern hemisphere (45N) one would expect to see approximately 12 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 4 per hour. As seen from the tropical southern latitudes (25S), morning rates would be near 8 per hour as seen from rural observing sites and 3 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.
The table below presents a list of radiants that are expected to be active this week. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.
|SHOWER||DATE OF MAXIMUM ACTIVITY||CELESTIAL POSITION||ENTRY VELOCITY||CULMINATION||HOURLY RATE||CLASS|
|RA (RA in Deg.) DEC||Km/Sec||Local Standard Time||North-South|
|December Phoenicids (PHO)||Dec 06||00:46 (016) -53||22||20:00||<1 – <1||III|
|Dec. Phi Cassiopeiids (DPC)||Dec 05||01:33 (023) +53||19||21:00||<1 – <1||IV|
|Northern Taurids (NTA)||Nov 11||05:00 (075) +25||29||00:00||2 – 1||II|
|November Orionids (NOO)||Nov 29||06:08 (092) +15||44||01:00||3 – 3||II|
|Monocerotids (MON)||Dec 09||06:20 (095) +09||41||01:00||<1 – <1||II|
|Geminids (GEM)||Dec 13||06:55 (104) +34||35||02:00||1 – <1||I|
|Puppid-Velids (PUP)||Dec 07||08:00 (120) -45||40||03:00||<1 – 1||II|
|Sigma Hydrids (HYD)||Dec 06||08:00 (120) +04||62||03:00||3 – 3||II|
|Dec. Leonis Minorids (DLM)||Dec 17||09:20 (140) +36||64||04:00||<1 – <1||II|
|Psi Ursa Majorids (PSU)||Dec 05||11:07 (167) +43||61||06:00||1 – <1||IV|
|Dec. Kappa Draconids (KDR)||Dec 03||12:24 (186) +70||43||07:00||<1 – <1||IV|
|Nov. Iota Draconids (NID)||Nov 26||12:40 (190) +64||44||07:00||<1 – <1||IV|
|Dec. Alpha Draconids (DAD)||Dec 08||13:01 (210) +60||43||08:00||<1 – <1||IV|