Meteor Activity Outlook for December 17-23, 2011

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

No matter where you live, the first half of December provides some of the best meteor activity of the year. Unfortunately in 2011, the moon will spoil much of this activity as I reaches its full phase on the 10th. 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 14. 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 it last quarter phase on Sunday December 18th. The half illuminated moon is still very bright and must be kept out of your field of view for successful meteor observations. During this period, the evening hours, which are unfortunately much less active with meteors, will be completely free of any interfering moonlight.  As the week progresses the moon will wane in phase and will rise approximately forty-five minutes later with each passing night. With this scenario, viewing conditions during the more active morning hours will improve with each passing night. The estimated total hourly rates for evening observers this week is near five as seen from the northern hemisphere and three as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near twelve two as seen from mid-northern latitudes and eight from mid-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. Morning rates are reduced due to moonlight.

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 December 17/18. These positions do not change greatly day to day so the listed coordinates may be used during this entire period..

The following showers are expected to be active this weekNow that particles produced by comet 2P/Encke are no longer encountering the Earth, the Taurid showers for 2011 are over and we resume reporting activity from the Antihelion (ANT) radiant. This is not a true radiant but rather activity caused by the Earth’s motion through space. As the Earth revolves around the sun it encounters particles orbiting in a prograde motion that are approaching their perihelion point. They all appear to be radiating from an area near the opposition point of the sun, hence the name Antihelion. These were once recorded as separate showers throughout the year but it is now suggested to bin them into a category separate from true showers and sporadics. This radiant is a very large oval some thirty degrees wide by fifteen degrees high. Activity from this radiant can appear from more than one constellation. The position listed here is for the center of the radiant which is currently located at 06:36 (099) +23. This position lies in western Gemini, three degrees southwest of the third magnitude star Epsilon Geminorum. Antihelion activity may also appear from eastern Taurus, northeastern Orion, or southern Auriga. This radiant is best placed near midnight local standard time (LST), when it lies on the meridian and is located highest in the sky. Rates at this time should be near two per hour as seen from the northern hemisphere and one per hour from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

The last of the Monocerotids (MON) may be seen this weekend from a radiant located at 07:03 (106) +07. This position lies on the Monoceros/Canis Minor border, ten degrees west of the brilliant zero magnitude star Procyon (Alpha Canis Minoris). Rates would be less than one per hour no matter your location. 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.

The last of the Sigma Hydrids (HYD) may be seen this weekend from a radiant located at 08:54 (134) +00. This position lies in western Hydra, five degrees south of the third magnitude star Zeta Hydrae. Rates would be less than one per hour no matter your location. The Sigma Hydrids are best seen near 0300 LST when the radiant lies highest above the horizon. At 61 km/sec. the Sigma Hydrids produce mostly swift meteors.

The December Leonis Minorids (DLM) are active from a radiant located at 10:39 (160) +31. This position lies in eastern Leo Minor, ten degrees northeast of the third magnitude star Zeta Leonis. These meteors are best seen near 0500 LST when the radiant lies highest above the horizon. This shower peaks on December 20th so current rates would be near one per hour as seen from the northern hemisphere and less than one per hour as seen from south of the equator. At 64 km/sec. the December Leonis Minorids produce mostly swift meteors.

The Coma Berenicids (COM) are active from a radiant located at 11:51 (178) +18. This position actually lies in eastern Leo, two degrees north of the second magnitude star Denebola (Beta Leonis). These meteors are best seen near 0600 LST when the radiant lies highest above the horizon. This shower peaked on December 16th so current rates would be near one per hour no matter your location. This week will be your only opportunity to see these meteors as the shower will be over by the 23rd. At 65 km/sec. the Coma Berenicids produce mostly swift meteors.

Activity from the  Ursids (URS) may begin to appear this weekend from a radiant located at 13:58 (210) +76. This position lies in eastern Ursa Minor, fifteen degrees east of the second magnitude star Kochab (Beta Ursa Minoris). It must be remembered that the length of degrees are smaller in high declinations so the radiant is actually closer to this star than these figures inply. 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. Maximum activity is not expected until Friday December 23th, so current hourly rates would probably be less than one. On the morning of maximum, hourly rates of between 5-10 Ursids may be seen. At 33 km/sec. the Ursids produce mostly medium-slow meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately eight sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near three per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near five per hour as seen from rural observing sites and two per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Morning rates are reduced due to moonlight.:

The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
ANT Antihelions           06h 36m  +23    30     2     1
MON Monocerotids          07h 03m  +07    41    <1    <1
HYD Sigma Hydrids         08h 54m  +00    61    <1    <1
DLM Dec Leonis Minorids   10h 39m  +31    64     1     1
COM Coma Berenicids       11h 51m  +18    65     1     1
URS Ursida                13h 58m  +76    33    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Meteor Activity Outlook for December 3-9, 2011

The following is a slightly edited version of Bob Lunsford’s excellent weekly summary of meteor activity. The original version can be found at the American Meteor Society’s site.

No matter where you live, the first half of December provides some of the best meteor activity of the year. Unfortunately in 2011, the moon will spoil much of this activity as I reaches its full phase on the 10th. 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 14. 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 waxes from half illuminated to nearly full by the end of the period. This weekend the waxing gibbous moon will set during the early morning hours, allowing a few hours of observing under dark skies between moon set and the start of morning twilight. The estimated total hourly rates for evening observers this week is near three as seen from the northern hemisphere and two as seen from the southern hemisphere. For morning observers the estimated total hourly rates should be near twenty two as seen from mid-northern latitudes and eighteen from mid-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. Evening rates are reduced due to moonlight.

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 December 3/4. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers 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 last of the Northern Taurids (NTA) for 2011 will be seen this week from a large radiant centered at 05:09 (077) +26. This position lies in eastern Taurus, five degrees southwest of the second magnitude star El Nath (Beta Tauri). The radiant is best placed near midnight LST, when it lies highest above the horizon. Since the radiant is large, Northern Taurid meteors may also appear to come from southern Auriga, southeastern Perseus, northern Orion, and western Gemini as well as Taurus. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. Expected rates would be near two per hour, no matter your location.

The November Orionids (NOO) were recently discovered by Sirko Molau and Jueregen Rendtel by analyzing video data from the IMO network. For years this radiant was lost in the maze of radiants active this time of year. Due to the low activity, visual observers were unable to detect this shower. This shower is active from November 18 through December 9. Maximum activity occurred on November 30. Once you know the radiant in advance, this shower is actually quite noticeable, producing an average of two shower members per hour near maximum. The radiant is currently located at 06:16 (094) +15. This position lies in northeastern Orion, seven degrees northeast of the orange first magnitude star Betelgeuse (Alpha Orionis). These meteors are best seen near 0100 LST when the radiant lies on the meridian and highest above the horizon. At 44 km/sec. the November Orionids produce mostly medium velocity meteors.

The Monocerotids (MON) are active from December 7th through the 18th. Peak activity occurs on December 8th. On the night of maximum activity the radiant is located at 06:37 (099) +08. This position lies in northern Monoceros, eight degrees south of the second magnitude star Alhena (Gamma Geminorum). Rates at maximum should be near one per hour no matter your location. 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 weekend from a radiant located at 06:55 (104) +34. This position lies in northern Gemini, near the fourth magnitude star Theta Geminorum. Expected rates this weekend would only be near one per hour as maximum is still ten days 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 14, 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 seeing no more than 20-30 meteors per hour. 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 08:05 (121) -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 20. Maximum activity occurs on December 6 from a radiant located at 08:11 (122) +03. This position lies on the Hydra/Canis Minor border, seven degrees southeast of the brilliant zero magnitude star Procyon (Alpha Canis Minoris). These meteors are best seen near 0300 LST when the radiant lies highest above the horizon. Current rates would be near two per hour no matter your location. At 61 km/sec. the Sigma Hydrids produce mostly swift meteors.

Activity from the December Leonis Minorids (DLM) begin next week from a radiant located at 09:56 (149) +37. This position lies in central Leo Minor, seven degrees northeast of the fourth magnitude star Alpha Lyncis. These meteors are best seen near 0500 LST when the radiant lies highest above the horizon. This shower peaks on December 20th so current rates would be near one per hour as seen from the northern hemisphere and less than one per hour as seen from south of the equator. At 64 km/sec. the December Leonis Minorids produce mostly swift meteors.

Another shower verified by video means are the Psi Ursa Majorids (PSU). This shower is active from November 29-December 13 with maximum activity occurring on December 5. On Tuesday 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. At 61km/sec., the average Psi Ursa Majorid meteor would be swift.

Another shower verified by video means are the December Kappa Draconids (KDR). 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. Current rates would most likely be less than one per hour. At 43km/sec., the average December Kappa Draconid meteor would be of medium velocity.

Lastly, the December Alpha Draconids (DAD) are active beginning Sunday from a radiant located at 13:31 (203) +60. This position actually lies in northeastern Ursa Major, five degrees north of the second magnitude double star Mizar (Zeta 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. Maximum activity is expected on Monday December 5th, but hourly rates would probably be less than one no matter your location. At 44 km/sec. the Alpha Draconids produce mostly medium speed meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately twelve sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near two per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near six per hour as seen from rural observing sites and one per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Evening rates are reduced due to moonlight.

The list below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
PHO Dec Phoenicids        00h 46m  -52    18    <1    <1
NTA Northern Taurids      05h 09m  +26    29     2     2
NOO November Orionids     06h 16m  +15    44     2     2
MON Monocerotids          06h 37m  +08    41     1     1
GEM Geminids              06h 55m  +34    35     1     1
PUP Puppids-Velids        08h 05m  -45    40    <1     2
HYD Sigma Hydrids         08h 11m  +03    61     2     2
DLM Dec Leonis Minorids   09h 56m  +37    64     1    <1
PSU Psi Ursa Majorids     11h 07m  +43    61    <1    <1
KDR Dec Kappa Draconids   12h 24m  +70    43    <1    <1
DAD Dec Alpha Draconids   13h 31m  +60    44    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Meteor Activity Outlook for December 18-24, 2010

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

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 14. 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 January. 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 full phase on Tuesday December 21st. At this time the moon lies opposite the sun and is above the horizon all night long from most locations. This is the worst time to attempt to view meteor activity as the bright moonlight will obscure all but the brightest meteors. The estimated total hourly rates for evening observers this week is ~3 from the northern hemisphere and ~2 for observers south of the equator. For morning observers the estimated total hourly rates should be ~10 from the northern hemisphere and ~9 as seen from the southern hemisphere. 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. Rates are reduced during this period due to moonlight.

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 December 18/19. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week. The detailed descriptions will be continued next week when the moonlight is not as intense.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
ANT Antihelions           06h 40m  +23    30     2     2
MON Monocerotids          07h 08m  +07    41    <1    <1
GEM Geminids              07h 56m  +31    35     1     1
HYD Sigma Hydrids         08h 56m  +00    61    <1    <1
DLM Dec Leonis Minorids   10h 44m  +31    71     1    <1
COM Coma Berenicids       11h 48m  +18    65     2    <1
URS Ursids                14h 12m  +75    33    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a
        dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Meteor Activity Outlook for December 11-17, 2010

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

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 14. 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 January. 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 first quarter phase on Sunday December 12th. At this time the moon lies ninety degrees east of the sun and sets near midnight local standard time (LST) for those located in the mid-northern latitudes. Later next week the waxing gibbous moon remains above the horizon most of the night making meteor observing difficult. The estimated total hourly rates for evening observers this week is ~8 from the northern hemisphere and ~2 for observers south of the equator. For morning observers the estimated total hourly rates should be ~45 from the northern hemisphere and ~20 as seen from the southern hemisphere. 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. Evening rates are reduced this week due to moonlight.

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 December 11/12. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

Antihelions (ANT)

Now that the activity from particles produced by comet 2P/Encke has ceased encountering the Earth, the Taurid showers for 2010 are over and we resume reporting activity from the Antihelion (ANT) radiant. This is not a true radiant but rather activity caused by the Earth’s motion through space. As the Earth revolves around the sun it encounters particles orbiting in a prograde motion that are approaching their perihelion point. They all appear to be radiating from an area near the opposition point of the sun, hence the name Antihelion. These were once recorded as separate showers throughout the year but it is now suggested to bin them into their category separate from true showers and sporadics. This radiant is a very large oval some thirty degrees wide by fifteen degrees high. Activity from this radiant can appear from more than one constellation. The position listed here is for the center of the radiant which is currently located at 06:12 (093) +23. This position lies in western Gemini near the fourth magnitude star Eta Geminorum. Antihelion activity may also appear from eastern Taurus, northeastern Orion, or southern Auriga. This radiant is best placed near midnight LST when it lies on the meridian and is highest in the sky. Rates at this time should be ~3 per hour as seen from the northern hemisphere and ~2 per hour from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

Monocerotids (MON)

The Monocerotids (MON) are active from December 7th through the 18th. Peak activity occurred on December 8th. The radiant is currently located at 06:48 (102) +08. This position lies in northwestern Monoceros halfway between the bright stars Betelgeuse (Alpha Orionis) and Procyon (Alpha Canis Minoris). Current rates should be ~1 per hour no matter your location. 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.

Geminids (GEM)

The Geminids (GEM) reach maximum activity on Monday evening/Tuesday morning December 13/14 when in excess of 60 shower members can be seen each hour from rural observing sites. The radiant is located at 07:28 (112) +32. This position lies in northern Gemini near the fourth magnitude star Rho Geminorum. This shower should be very activie this weekend with hourly rates near midnight ranging from 10 Friday night/Saturday morning to 25 Saturday night/Sunday morning. Although Geminid meteors can be seen all night long, they are best seen near 0200 LST when the radiant lies highest above the horizon. 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. This is one of the few displays that can be well seen prior to midnight. Unfortunately the first quarter moon will reduce rates until it approaches the western hornizon near midnight.

Puppid-Velids (PUP)

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. The center of this activity is currently located at 08:08 (126) -45. This position lies in western Vela, five degrees northeast of the second magnitude star Gamma Velorum. Peak rates occurred near December 7 so current activity is waning 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. At 40 km/sec. the Puppid-Velids produce meteors of average velocity.

Sigma Hydrids (HYD)

The Sigma Hydrids (HYD) are active from November 26 through December 20. Maximum activity occurred on December 6. The radiant is currently located at 08:16 (129) +02. This position lies in western Hydra, just below the group of fourth magnitude stars that make up the “head” of the water serpent. These meteors are best seen near 0300 LST when the radiant lies highest above the horizon. Current rates would be ~1 per hour no matter your location. At 61 km/sec. the Sigma Hydrids produce mostly swift meteors.

December Leonis Minorids (DLM)

The December Leonis Minorids (DLM) are active from a radiant located at 10:22 (155) +34. This position lies in central Leo Minor, approximately ten degrees north of the third magnitude star Zeta Leonis. These meteors are best seen near 0500 LST when the radiant lies highest above the horizon. This shower peaks on December 20th so current rates would be ~1 per hour as seen from the northern hemisphere and < 1 per hour as seen from south of the equator. At 64 km/sec. the December Leonis Minorids produce mostly swift meteors.

Coma Berenicids (COM)

Activity from the Coma Berenicids (COM) has just begun for 2010. The radiant is located at 11:30 (172) +19. This position actually lies in eastern Leo, six degrees northwest of the second magnitude star Denebola (Beta Leonis). These meteors are best seen near 0600 LST when the radiant lies highest above the horizon. This shower peaks on December 16th so current rates would be ~2 per hour as seen from the northern hemisphere and ~1 per hour as seen from south of the equator. At 65 km/sec. the Coma Berenicids produce mostly swift meteors.

Psi Ursa Majorids (PSU)

Another shower verified by video means are the Psi Ursa Majorids (PSU). This shower is active from November 29-December 13 with maximum activity occurring on December 5. The radiant is currently located at 11:55 (179) +41. 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. With the shower ending this weekend, current rates would most likely be < 1 per hour. At 61km/sec., the average Psi Ursa Majorid meteor would be swift.

December Alpha Draconids (DAD)

Lastly, the December Alpha Draconids (DAD) are active from a radiant located at 14:00 (210) +58. This position actually lies in northeastern Ursa Major, six degrees northeast of the second magnitude double star Mizar (Zeta 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. Expected hourly rates would be < 1 no matter your location. At 44 km/sec. the Alpha Draconids produce mostly medium speed meteors.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
ANT Antihelions           06h 12m  +23    30     3     2
MON Monocerotids          06h 48m  +08    41     1     1
GEM Geminids              07h 28m  +32    35    25     5
PUP Puppid-Velids         08h 08m  -45    40    <1     2
HYD Sigma Hydrids         08h 16m  +02    61     1     1
DLM Dec Leonis Minorids   10h 22m  +34    71     1    <1
COM Coma Berenicids       11h 30m  +19    65     2    <1
PSU Psi Ursa Majorids     11h 55m  +41    61    <1    <1
DAD Dec Alpha Draconids   14h 00m  +58    44    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a
        dark site
NH - Northern Hemisphere
SH - Southern Hemisphere

Dec 7/8/9/10 Meteors

The Geminids (GEM) saw an increase in activity last night (Dec 9/10) and for the first time this year clearly outproduced some of the other active showers such as the Sigma Hydrids (HYD).  Rates should continue to slowly increase every night until Sunday/Monday night when rates will skyrocket as we close in on Tuesday morning’s peak.

Down in Hermosillo (Mexico), Salvador Aguirre counted 7 GEMs in 2 hours of observing under a magnitude +6.2 sky. To see more details visit his blog (in Spanish).

The International Meteor Organization has there ZHR Live page for the 2010 Geminids up and running. Based on the observations of Salvador and other observers, the Geminid ZHR for last night was ~13 per hour. Remember the ZHR is a normalized rate to near perfect conditions (no obstructions, radiant overhead and pitch black skies with a limiting magnitude of +6.5). For most of us in light polluted areas the actual rate is much lower. So for most of us the Geminids are currently only producing 2-3 meteors per hour.

The number of bright (0th magnitude or brighter) meteors has been very high the last 3 nights. Usually my fireball camera only catches a dozen or so per night but the last 3 nights have seen 21, 27 and 23 meteors. Very few of these have been Geminids (that will surely change real soon). Three minor showers have been producing a steady rate of bright ones, the Sigma Hydrids (HYD), December Leonis Minorids (DLM) and Monocerotids (MON).

Last night also marked SALSA3′s 76th consecutive night with a meteor detection. Not sure if this is a MetRec/IMO Video Group record but it must be close.

Obs  Date(UT)      Time    TOT SPO ANT GEM HYD PHO PSU PUP DAD DLM MON
SAL3 2010-12-10   12h 09m   43  6   1   10  4   -   0   2   0   2   2
ALLS 2010-12-10   10h 31m   23  6   1   5   5   -   0   1   0   2   3
SAL3 2010-12-09   12h 08m   35  23  0   5   4   0   0   0   0   1   2
ALLS 2010-12-09   12h 38m   27  13  0   0   4   0   1   0   2   4   3
SAL3 2010-12-08   11h 25m   32  21  1   0   5   0   0   0   1   2   2
ALLS 2010-12-08   11h 38m   21  8   0   0   4   0   1   0   0   5   3 

SAL3 - SALSA3 camera in Tucson (Carl Hergenrother)
ALLS - Near all-sky camera in Tucson (Carl Hergenrother)
VIST - Visual observations from Tucson (Carl Hergenrother)
SDG - Camera in San Diego operated by Bob Lunsford
Time - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelions   
GEM - Geminids
HYD - Sigma Hydrids
PHO - Phoenicids
PSU - Psi Ursa Majorids
PUP - Puppids-Vellids
DAD - December Alpha Draconids
DLM - December Leonis Minorids
MON - Monocerotids

Dec 6/7 Meteors

Last night we said goodbye to the November Orionids (NOO) and the Kappa Draconids (KDR) and hello to the Monocerotids (MON). Interestingly the NOO and MON were both produced by Comet Mellish. The NOO about 4000-5000 years ago while the MON were released more recently. For a bit more about these 2 showers see my previous post from a few days ago.

After the Sporadics (which are meteors not affiliated with any known shower, or at least not affiliated anymore), the best producers are the Geminids and Sigma Hydrids. Both showers have been producing some nice fireballs. Salvador Aguirre’s all-sky cam has been picking up a number of these objects over Hermosillo, Sonora, Mexico. You can see video of some of his detections on his blog (in Spanish).

Obs  Date(UT)      Time    TOT SPO ANT GEM HYD PHO PSU PUP DAD DLM MON
SAL3 2010-12-07   07h 57m   25  12  1   3   4   0   1   1   0   1   2 
ALLS 2010-12-07   12h 37m   9   5   0   0   3   0   0   1   0   0   0 

SAL3 - SALSA3 camera in Tucson (Carl Hergenrother)
ALLS - Near all-sky camera in Tucson (Carl Hergenrother)
VIST - Visual observations from Tucson (Carl Hergenrother)
SDG - Camera in San Diego operated by Bob Lunsford
Time - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelions   
GEM - Geminids
HYD - Sigma Hydrids
PHO - Phoenicids
PSU - Psi Ursa Majorids
PUP - Puppids-Vellids
DAD - December Alpha Draconids
DLM - December Leonis Minorids
MON - Monocerotids

Meteor Activity Outlook for December 4-10, 2010

The Meteor Activity Outlook is a weekly summary of expected meteor activity written by Robert Lunsford, Operations Manager of the American Meteor Society and contributor to this blog. The original unedited version of this week’s Meteor Activity Outlook can be found at the American Meteor Society’s site.

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 14. 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 January. 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 Sunday December 5th. At this time the moon lies near the sun and cannot be seen at night. Later next week the waxing crescent moon enters the evening sky but still sets long before the busy morning hours arrive. The estimated total hourly rates for evening observers this week is ~5 from the northern hemisphere and ~3 for observers south of the equator. For morning observers the estimated total hourly rates should be ~15 from the northern hemisphere and ~13 as seen from the southern hemisphere. 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.

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 December 4/5. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

December Phoenicids (PHO)

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 01:08 (017) -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) 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.

Northern Taurids (NTA)

The center of the large Northern Taurid (NTA) radiant lies at 05:12 (078) +26. This area of the sky is located in eastern Taurus, five degrees southwest of the second magnitude star El Nath (Beta Tauri). These meteors are best seen near midnight, when the radiant lies highest above the horizon. This shower peaked on November 13, so rates are falling should be ~2 per hour. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. This shower is also responsible for many of the fireball reports seen in November.

November Orionids (NOO)

The November Orionids (NOO) were recently discovered by analyzing video data. For years it was lost in the maze of radiants active this time of year. Due to the low activity, visual observers were unable to detect this shower. This shower is active from November 18 through December 9. Maximum activity occurs on November 30. Once you know the radiant in advance, this shower is actually quite noticeable, producing an average of 2 shower members per hour near maximum. The radiant is currently located at 06:20 (095) +15. This position lies in northeastern Orion, eight degrees northeast of the orange first magnitude star Betelgeuse (Alpha Orionis). These meteors are best seen near 0100 LST when the radiant lies on the meridian and highest above the horizon. At 44 km/sec. the November Orionids produce mostly medium velocity meteors.

Monocerotids (MON)

The Monocerotids (MON) are active from December 7th through the 18th. Peak activity occurs on December 8th. On the night of maximum activity the radiant is located at 06:37 (099) +08. This position lies in northern Monoceros, eight degrees south of the second magnitude star Alhena (Gamma Geminorum). Rates at maximum should be near two per hour no matter your location. 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.

Geminids (GEM)

Geminid (GEM) activity begins this weekend from a radiant located at 07:16 (109) +33. This position lies in northern Gemini, four degrees west of the second star Castor (Alpha Geminorum). Expected rates this weekend would only be near one per hour as maximum is still ten days 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 14, when rates can surpass 60 shower members per hour as seen from dark sites. 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.

Puppid-Velids (PUP)

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 10. Actual hourly rates will be much less unless you happen to be observing from the deep Southern Hemisphere. The center of this activity is currently located at 08:08 (122) -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. At 40 km/sec. the Puppid-Velids produce meteors of average velocity.

Sigma Hydrids (HYD)

The Sigma Hydrids (HYD) are active from November 26 through December 20. Maximum activity occurs on December 6 from a radiant located at 08:16 (124) +03. This position lies on the Hydra/Canis Minor border, seven degrees southeast of the brilliant zero magnitude star Procyon (Alpha Canis Minoris). These meteors are best seen near 0300 LST when the radiant lies highest above the horizon. Current rates would be near two per hour no matter your location. At 61 km/sec. the Sigma Hydrids produce mostly swift meteors.

December Leonis Minorids (DLM)

Activity from the December Leonis Minorids (DLM) begin this weekend from a radiant located at 09:56 (149) +37. This position lies in central Leo Minor, seven degrees northeast of the fourth magnitude star Alpha Lyncis. These meteors are best seen near 0500 LST when the radiant lies highest above the horizon. This shower peaks on December 20th so current rates would be near one per hour as seen from the northern hemisphere and less than one per hour as seen from south of the equator. At 64 km/sec. the December Leonis Minorids produce mostly swift meteors.

Psi Ursa Majorids (PSU)

Another shower verified by video means are the Psi Ursa Majorids (PSU). This shower is active from November 29-December 13 with maximum activity occurring on December 5. The radiant is currently located at 11:12 (168) +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. At 61km/sec., the average Psi Ursa Majorid meteor would be swift.

December Kappa Draconids (KDR)

Another shower verified by video means are the December Kappa Draconids (KDR). This shower is active from November 30-December 6 with maximum activity occurring on December 3. Activity from this source is not expected this weekend. On the night of maximum the radiant will be located at 12:30 (187) +69. This position lies in extreme western Draco, very 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. Current rates would most likely be less than one per hour. At 43km/sec., the average December Kappa Draconid meteor would be of medium velocity.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
PHO December Phoencids    01h 08m  -53    18    <1    <1
NTA Northern Taurids      05h 12m  +26    29     2     2
NOO November Orionids     06h 20m  +15    44     2     2
MON Monocerotids          06h 37m  +08    41     2     2
GEM Geminids              07h 16m  +33    35     1    <1
PUP Puppid-Velids         08h 08m  -45    40    <1     5
HYD Sigma Hydrids         08h 16m  +03    61     2     2
DLM Dec Leonis Minorids   09h 56m  +37    71    <1    <1
PSU Psi Ursa Majorids     11h 12m  +43    61    <1    <1
KDR Dec Kappa Draconids   12h 30m  +69    43    <1    <1

RA - Right Ascension
DEC - Declination
Vel - Velocity relative to Earth (in km per sec)
Rates - Rate of visible meteors per hour from a
        dark site
NH - Northern Hemisphere
SH - Southern Hemisphere
Follow

Get every new post delivered to your Inbox.

Join 107 other followers