Meteor Activity Outlook for November 24-30, 2012

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.

As seen from the northern hemisphere, meteor rates continue to be strong in November. While no major activity is expected this month, the two Taurid radiants plus the Leonids keep the skies active. The addition of strong sporadic rates make November one of the better months to view meteor activity from north of the equator. Skies are fairly quiet as seen from the
southern hemisphere this month. Activity from the three showers mentioned above may be seen from south of the equator, but the sporadic rates are much lower than those seen in the northern hemisphere.

During this period the moon reaches its full phase on Wednesday November 28th. At this time the moon is located opposite the sun and will remain in the sky all night long. This weekend the waxing gibbous moon will set during the early morning hours and will allow a couple of hours between moon set and morning twilight to view the meteor activity under good conditions. The estimated total hourly meteor rates for evening observers this week is near three for observers located at mid-northern latitudes and two for observers in mid-southern latitudes. For morning observers the estimated total hourly rates should be near eighteen from the mid-northern hemisphere and ten from the mid-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 November 24/25. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following radiants are expected to be active this week:

Remnants from the famous Andromedid (AND) shower, noted for intense storms during the 19th century, may still be seen throughout November. The current position of this large radiant is 01:38 (024) +41. This position lies in eastern Andromeda, close to the position occupied by the faint stat known as Upsilon Andromedae. The radiant is so diffuse that Andromedid meteors may be seen coming from Triangulum, northern Pisces, as well as Andromeda. Visual activity is expected to be low, but detectable. An inconspicuous maximum occurred on November 9, when this source was the 5th most active radiant in the sky. The Andromedid meteors are best seen near 2200 (10pm) local standard time (LST), when the radiant lies on the meridian and lies highest in the sky. At 19km/sec., the average Andromedid will appear as a very slow moving meteor.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed another active radiant in Taurus this time of year. Now that the Southern Taurids are no longer detectable, the Gamma Taurids (GTA) may be distinguished within the Taurid complex. The Gamma Taurid radiant is centered at 04:22 (065) +15. This area of the sky lies in western Taurus, three degrees southwest of the orange first magnitude star Aldebaran (Alpha Tauri). The radiant is best placed near 0100 LST, when it lies highest above the horizon. Maximum activity occurred on November 10th so current rates would be near one shower member per hour, no matter your location. Meteors from the Gamma Taurids strike the atmosphere at 27km/sec., which would produce meteors of slow velocity.

The Northern Taurids (NTA) are active from a radiant centered at 04:40 (070) +25. This area of the sky lies in northern Taurus, nine degrees north of the orange first magnitude star Aldebaran (Alpha Tauri). The radiant is best placed near 0100 LST, when it lies highest above the horizon. Maximum activity occurred on November 13th so current hourly rates would be near two from the northern hemisphere and one from south of the equator. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity.

The November Orionids (NOO) are now the most active radiant in the sky and will remain #1 throughout the remainder of November. This radiant is located at 05:50 (087) +15. This area of the sky is located on the Orion/Taurus border, eight degrees north of the first magnitude orange star Betelgeuse (Alpha Orionis). The peak occurs on November 30th so current rates will be 2-3 per hour, no matter your location. If the moon lies above the horizon rates will be lower due to the lunar glare. The radiant is best placed for viewing near 0200 LST when it lies on the meridian and is highest above the horizon. With an entry velocity of 44 km/sec., the November Orionids would be of medium speed.

The Leonids (LEO) are still active from a radiant located at 10:34 (159) +20. This position lies in northwestern Leo, two degrees east of the second magnitude double star Algeiba (Gamma Leonis). Current rates should be 1-2 per hour, no matter your location. The Leonid radiant is best placed during the last hour before morning twilight when the radiant lies highest in a dark sky. Leonids may be seen from the southern hemisphere but the viewing conditions are not quite as favorable as those north of the equator.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed an active radiant in Draco this time of year. The November Iota Draconids (NID) radiant is located at 12:44 (191) +68. This area of the sky lies in western Draco, two degrees southeast of the fourth magnitude star Kappa Draconis. The radiant is best placed near 0100 LST, when it lies highest above the horizon. Maximum activity occurs on November 26th so current rates would be less than one shower member per hour, no matter your location. Due to the high northerly declination of the radiant these meteors are not visible from most of the southern hemisphere. Only southern equatorial regions would have any chance of seeing activity from this source Meteors from the November Iota Draconids strike the atmosphere at 43km/sec., which would produce meteors of medium velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately ten 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. 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 but may be used
for the entire period.

Andromedids (AND) – 01:38 (024) +41   Velocity – 19km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr.

Gamma Taurids (GTA) – 04:22 (065) +15   Velocity – 29km/sec.
Northern Hemisphere – 1 per hr.   Southern Hemisphere – 1 per hr.

Northern Taurids (NTA) – 04:40 (070) +25   Velocity – 29km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 1 per hr.

November Orionids (NOO) – 05:50 (087) +15   Velocity – 44km/sec.
Northern Hemisphere – 3 per hr.   Southern Hemisphere – 2 per hr.

Leonids (LEO) – 10:34 (159) +20   Velocity – 71km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 1 per hr.

November Iota Draconids (NID – 12:44 (191) +68   Velocity – 43km/sec.
Northern Hemisphere -<1 per hr.   Southern Hemisphere – <1 per hr.

Clear Skies!
Robert Lunsford
American Meteor Society

Meteor Activity Outlook for November 10-16, 2012

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.

As seen from the northern hemisphere, meteor rates continue to be strong in November. While no major activity is expected this month, the two Taurid radiants plus the Leonids keep the skies active. The addition of strong sporadic rates make November one of the better months to view meteor activity from north of the equator. Skies are fairly quiet as seen from the
southern hemisphere this month. Activity from the three showers mentioned above may be seen from south of the equator, but the sporadic rates are much lower than those seen in the northern hemisphere.

During this period the moon reaches its new phase on Tuesday November 13th. At this time the moon is located near the sun and cannot be seen at night. This weekend the waning crescent moon will rise during the late morning hours, but it will rise so late and be so thin that it will not interfere with meteor observing. As the week progresses the moon will enter the evening sky but will set shortly after dusk, not causing any problems for watching meteor activity. The estimated total hourly meteor rates for evening observers this week is near five for observers located at mid-northern latitudes and three for observers in mid-southern latitudes. For morning observers the estimated total hourly rates should be near twenty from the mid-northern hemisphere and twelve from the mid-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 November 10/11. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following radiants are expected to be active this week:

Remnants from the famous Andromedid (AND) shower, noted for intense storms during the 19th century, may still be seen throughout November. The current position of this large radiant is 01:32 (023) +31 . This position lies on the Pisces/Triangulum border, very close to the large, but faint spiral galaxy known as M33. If you are not familiar with M33, then the nearest bright star is second magnitude Mirach (Beta Andromedae), which lies five degrees to the northwest. The radiant is so diffuse that Andromedid meteors may be seen coming from southern Andromeda, Triangulum, and northwestern Aries as well as eastern Pisces. Visual activity is expected to be low, but detectable. An inconspicuous maximum occurs on November 9, when this source is the 5th most active radiant in the sky. The Andromedid meteors are best seen near 2200 (10pm) local standard time (LST), when the radiant lies on the meridian and lies highest in the sky. At 19km/sec., the average Andromedid will appear as a v
ery slow moving meteor.

The Northern Taurid (NTA) radiant is the most active source of meteor activity this week, producing 3-4 shower members per hour, depending on your location. The radiant is centered at 03:52 (058) +22. This area of the sky lies in  western Taurus just one degree south of the famous naked eye open cluster known as the Pleiades or the Seven Sisters. The radiant is best placed near 0100 LST, when it lies highest above the horizon. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. You must face in the general direction of the north and south Taurid radiants in order to tell them apart.

The Southern Taurid (STA) radiant is currently located at 04:00 (060) +15. This position lies in western Taurus, eight degrees southeast of the famous naked eye open cluster known as the Pleiades or the Seven Sisters. This radiant is also best placed near 0100 LST, when it lies on the meridian and is located highest in the sky. Maximum occurred on October 9th, so rates would now be near two per hour , no matter your location. With an entry velocity of 29 km/sec., the average Southern Taurid meteor would be of slow velocity.

The November Orionids (NOO) may be seen in small numbers beginning this week. The peak for this radiant is not until November 30th, so rates would be less than than one shower member per hour, no matter your location. The radiant is located at 05:08 (077) +16. This area of the sky is located on the Orion/Taurus border, seven degrees east of the first magnitude orange star Aldebaran (Alpha Tauri). This location is close to the Taurid complex, but far enough east to be distinguishable. The faster velocity of the November should help distinguish these meteors from the slower, but more numerous Taurids. The radiant is best placed for viewing near 0200 LST when it lies on the meridian and is highest above the horizon. With an entry velocity of 44 km/sec., the November Orionids would be of medium speed.

The Orionids (ORI) are still active but rates are slowing falling with each passing night. The radiant located at 07:28 (112) +16. This area of the sky is located in southern Gemini, twelve degrees east of the second magnitude star Alhena (Gamma Geminorum). The radiant is best placed for viewing near 0400 LST when it lies on the meridian and is highest above the horizon. Orionid meteors are equally well seen either side of the equator. With an entry velocity of 67 km/sec., most activity from this radiant would be swift.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed a radiant active in the constellation of Cancer this time of year. Rates are weak but detectable under moonless skies. The Zeta Cancrids (ZCN) are active throughout November but activity dates and radiant positions are poorly determined. During this period the radiant lies near 08:24 (126) +08.  This area of the sky is located in southern Cancer, one degree southeast of the third magnitude star Al Tarf (Beta Cancri). This area of the sky may be more easier found using the “head” of Hydra as a guide, as it lies only five degrees to the southeast. The radiant is best placed for viewing near 0500 LST when it lies on the meridian and is highest above the horizon.  With an entry velocity of 70 km/sec., most activity from this radiant would be swift. These meteors can be seen equally well from either side of the equator.

The Leonids (LEO) are now the second most active radiant in the sky, producing 1-2 shower members per hour during the last couple of hours before dawn. The radiant is currently located at 10:00 (150) +24. This position lies in northwestern Leo, within the “sickle” of Leo, three degrees west of the third magnitude star Adhafera (Zeta Leonis). The Leonid radiant is best placed during the last hour before morning twilight when the radiant lies highest in a dark sky. Leonids may be seen from the southern hemisphere but the viewing conditions are not quite as favorable as those north of the equator.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately eleven sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near four 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.

The list below presents a summary of the expected activity this week. Rates and
positions are exact for Saturday night/Sunday morning, but may be used all week.

Andromedids (AND) – 01:32 (023) +31    Velocity 19km/sec
Northern Hemisphere – 1 per hr    Southern Hemisphere – <1 per hour

Northern Taurids (NTA) – 03:52 (058) +22    Velocity 29km/sec
Northern Hemisphere – 4 per hr    Southern Hemisphere – 3 per hour

Southern Taurids (STA) -04:00 (060) +15    Velocity 29km/sec
Northern Hemisphere – 2 per hr    Southern Hemisphere – 2 per hour

November Orionids (NOO)  05:08 (077) +16   Velocity 44km/sec
Northern Hemisphere – <1 per hr    Southern Hemisphere – <1 per hour

Orionids (ORI) 07:28 (112) +16    Velocity 67km/sec
Northern Hemisphere – 1 per hr    Southern Hemisphere – 1 per hour

Zeta Cancrids (ZCN)  08:24 (126) +08    Velocity 70km/sec
Northern Hemisphere – <1 per hr    Southern Hemisphere – <1 per hour

Leonids (LEO) 10:00 (150) +24    Velocity 71km/sec
Northern Hemisphere – 2 per hr    Southern Hemisphere – 1 per hour

Clear Skies!
Robert Lunsford
American Meteor Society

In the Transient Sky – November 2012

November 2012 Highlights
* Leonid meteor shower peaks on the morning of November 17 though rates will be low
* Jupiter and the Moon pair up on the evenings of the 1st and 28th
* Venus and Saturn pair up on the morning of the 26th-27th
* Venus, Mercury and Saturn are all visible in a line at the end of the month

Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <transientsky1@yahoo.com>.

Planets

Evening Planets

Mercury – Mercury starts the month very low in the southwest after dusk. It is probably too low for most observers. Luckily it appears in the morning at the end of the month.

Mars - Mars glows at a rather meager +1.2 magnitude this month low in the southwest after dusk. It is only visible for anout an hour after sunset as it continues its slow descent towards the horizon. Use the Moon to find Mars on the evenings of the 15th and 16th.

Jupiter – Jupiter is heading towards its December 2nd opposition. At the start of the month it rises in the northeast around 7:30 to 8:00 pm. On the evening of the first, it makes a spectacular pair with the Moon between the horns of Taurus. The two pair up again on the evening of the 28th. At magnitude -2.6 to -2.7 it is the brightest “star” in the sky with the exception of early morning Venus.

Morning Planets

Venus – Venus rises about 2 hours before the Sun this month. In a telescope the planet will appear more than half-illuminated (about 80%). At magnitude – 4.1, Venus is by far the brightest ‘star’ in the morning sky. This November Venus makes a close pairing with the star Theta Virginis on the 12th and 13th, a more distant pairing with 1st magnitude Spica on the 17th and a rather close pairing with Saturn on the 26th and 27th. The Moon also passes to the south of Venus on the morning of the 11th. During the last week of November, Venus, Saturn and Mercury

Saturn – Saturn is an early morning object. Venus passes very close to Saturn on the mornings of the 26th and 27th.

Mercury – The innermost planet pops above the southeast horizon just before dawn during the last week of the month. It is the lower left planet in a line made up of Saturn-Venus-Mercury.

Meteors

The year is usually split in 2 with January through June having low rates with few major showers while July through December have high rates with many major showers. Meteor activity is still near an annual this month.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During November mornings, 10 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

Leonids (LEO) [Max Date = Nov. 17, Max ZHR = ~10-15 per hour]

The Leonids are the result of dust released by Comet Tempel-Tuttle. The comet resides on an orbit that spans from just inside the orbit of the Earth (0.98 AU) to slightly beyond the orbit of Uranus (19.7 AU). It takes the comet ~33 years to orbit the Sun. The the comet last passed perihelion (closest distance to the Sun) in 1998 and was well observed at that time.

The first recorded appearance of the Leonids was in 902 AD when the shower was seen from Italy and Egypt. For the next few centuries, impressive Leonid displays were observed every 33 to 200 years or so.

Two Leonid storms stand out from all the others. On 1833 November 13, the entire eastern United States was awaken to a sight very few had every seen. The sky appeared to be filled with meteors. Modern researchers now know the cause of this outburst. It is estimated that a rate of up to ~70,000 meteors per hour was observed. That works out to ~20 meteor per second.

The 1833 storm marks the dawning of the modern age of meteor science. It was due to observations of this storm that astronomers first recognized that meteors originate in space. About 30 years later, after the discovery of Comets Swift-Tuttle (parent of the Perseids) and Tempel-Tuttle (the parent of the Leonids), the connection between comets and meteor showers was made.

The 1833 storm ranks as one of the 2 best meteor displays in recorded history. 133 years after the 1833 storm, the Leonids once again set the skies ablaze. On the night of 1966 November 17, the western United States experienced a storm just as strong as the 1833 storm.

When the comet returned in 1998, there were many predictions for spectacular Leonid activity. Though meteor rates never got close to that seen in 1833 or 1966, rates as high as a few thousand meteors per hour were observed in multiple years. The best meteor shower I have ever seen was the 1998 Leonid fireball display. Though I would observe Leonid displays with much higher rates of meteors, the sheer number of extremely bright meteors in 1998 was breathtaking.

Unfortunately no major display is forecast for 2012. Rather rates should be a meager 10-15 per hour for observers under dark skies.

 

The Leonids appear to come from an area in the “sickle” of Leo. This area, called the radiant, rises around midnight local time. It is best to wait till the radiant is high in the sky before looking for meteors (say 2am). The radiant is highest around the start of dawn. Meteors can appear anywhere in the sky so you don’t have to look at the radiant.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Info on many minor showers are provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the International Meteor Organization’s 2012 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None this month.

Binocular Comets (V = 6.0 – 8.0)

None this month

Small Telescope Comets (V = 8.0 – 10.0)

168P/Hergenrother

The surprise comet of the year, little 168P was only expected to brighten to magnitude 15 or so this apparition even though it passed within 0.42 AU of the Earth and 1.41 AU of the Sun in late October/early November. A number of outbursts and splitting events resulted in 168P brightening up to 9th magnitude. Recent large telescope observations have detected a secondary nucleus which split off from the main nucleus during on of the outbursts.

As of the 1st of the month, 168P is probably a little fainter than 10th magnitude as it slowly fades after its last outburst. Hopefully another outburst will occur and push the comet back into the realm of small telescope observation.

Meteor Activity Outlook for November 19-25, 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.

As seen from the northern hemisphere, meteor rates continue to be strong in November. While no major activity is expected this month, the two Taurid radiants plus the Leonids keep the skies active. The addition of strong sporadic rates make November one of the better months to view meteor activity from north of the equator. Skies are fairly quiet as seen from the southern hemisphere this month. Activity from the three showers mentioned above may be seen from south of the equator, but the sporadic rates are much lower than those seen in the northern hemisphereDuring this period the moon reaches its new phase on Thursday November 25th. At that time the moon will lie near the sun and will not be visible at night. This weekend the waning crescent moon will be a nuisance in the late morning sky but will not inhibit meteor watching. If the moon is above the horizon simple face in a direction in which it lies outside of your field of view. The moon will be less of a problem with each passing night as it approaches the sun. The estimated total hourly rates for evening observers this week is near four 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 fifteen as seen from mid-northern latitudes and twelve 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 slightly 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 November 19/20. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

Remnants from the famous Andromedid (AND) shower, noted for intense storms during the 19th century, may still be seen throughout November. The current position of this large radiant is 01:38 (024) +39. This position lies in central Andromeda, two degrees south of the fourth magnitude star Upsilon Andromedae. The radiant is so diffuse that Andromedid meteors may also be seen coming from Triangulum, extreme northwestern Perseus, and southeastern Cassiopeia as well as Andromeda. Visual activity is expected to be low, but detectable. An inconspicuous maximum occured on November 12. The Andromedid meteors are best seen near 2200 (10pm) LST (Local Standard Time), when the radiant lies on the meridian. At 19km/sec., the average Andromedid will appear as a very slow moving meteor.

The last of the Omicron Eridanids (OER) will be seen this weekend from a radiant located at 04:06 (061) -03. This position lies in northeastern Eridanus, fifteen degrees northwest of the bright zero magnitude star Rigel (Beta Orionis). The radiant is best placed near 0100 LST, when it lies highest above the horizon. Meteors from the Omicron Eridanids strike the atmosphere at 27km/sec., which would produce meteors of slow velocity. Expected rates from this weak shower would be less than one per hour, no matter your location.

The Northern Taurids (NTA) are active from a large radiant centered at 04:22 (066) +24. This position lies in central Taurus, seven degrees north of the bright first magnitude orange star Aldebaran (Alpha Tauri). The radiant is best placed near 0100 LST, when it lies highest above the horizon. Since the radiant is large, Northern Taurid meteors may also appear to come from southwestern Auriga, southeastern Perseus, northwestern Orion, 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 occurs 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 05:35 (084) +16. This position lies in northern Orion, nine degrees northwest of the orange first magnitude star Betelgeuse (Alpha Orionis). These meteors are best seen near 0200 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 Leonids (LEO) should peak on November 18th. Up to five Leonids an hour may be seen during the morning hours this weekend. Rates will fall as the week progresses. The radiant is currently located at 10:22 (155) +21. This position lies in western Leo only two degrees north of the third magnitude star Algeiba (Gamma Leonis). At 71km/sec., the average Leonid is swift with a high percentage of trains. These meteors are best seen during the last hour before the onset of morning twilight, when the radiant lies highest above the horizon in a dark sky.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately nine 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 slightly 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
AND Andromedids           01h 38m  +39    19    <1    <1
OER Omicron Eridanids     04h 06m  -03    27    <1    <1
NTA Northern Taurids      04h 22m  +24    29     2     2
NOO November Orionids     05h 35m  +16    44     1     1
LEO Leonids               10h 22m  +21    71     3     2

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

Nov 25/26 to 29/30 Meteors

October turned out to be another great month for meteor observing. For the 2nd month in a row a meteor was observed on every single night in the month. As of last night (stats to be posted in the next summary) the consecutive meteor detection streak stands at 67 nights. That’s about 1/6th of a year which is rather impressive. With no major storms in the forecast the streak should continue on for some time. The downside is that lack of clouds means lack of rain and this dry spell isn’t helping the long-term drought here in the southwestern US.

For the month of November, the SALSA3 camera detected 732 meteors over all 31 nights. Total time on the sky was 291.4 hours.

The breakdown of detected meteors for the month is:

Obs  Mon Time   TOT SPO ANT NTA STA ORI ETT BCN AND LEO NOO OER AMO PHO KDR PSU HYD
SAL3 Oct 291.4h 732 414  13  69  52  41  6   8   8   79  22  5   3   1   1   3   8

Two interesting meteor events happened this past week. First a brilliant fireball was seen over southern AZ on the night of Nov 28/29 at ~11:53 pm. The fireball was picked up by my all-sky cam and was even seen as far south as Hermosillo were Salvador Aguirre’s camera picked it up. I’ll have more on this event later, for now follow the latest on James Gamble’s excellent El Paso AllSky blog.

The second event of the past week was enhanced activity from the little known November Orionids (NOO) shower. This shower is not to be confused with the very well observed Orionids in October. The NOO was created by Comet Mellish, a bright Halley-type comet with a ~145 year period. Only seen in 1917, the comet is due back around 2062 (a year after Halley’s next return). A recent study by Peter Veres et al. found that the NOO were released by Comet Mellish between 4000-5000 years ago. Another shower, the December Monocerotids, were also created by C/Mellish but were released more recently.

Bob Lunsford was the first to call attention to the uptick in NOO activity with a post on the meteorobs list. He detected 8 NOO on the night of Nov 28/29. My cameras also saw enhanced activity that night with SALSA3 seeing 8 NOO and the near all-sky camera 5 NOO. On most nights rates were only 1 or 2 per night. Only the nights of Nov 27/28 (4 total) and 28/29 (13 total) saw any enhancement. This activity does seem to have occurred a few nights before the predicted peak of the NOO.

Though a very minor shower visually, radar observations by the Canadian Meteor Orbit Radar tell a different story. For the radar the NOO is one of the best meteors during the last third of the year. Radar can detect meteors much smaller and fainter than what the eye can see. This means that most of the shower’s mass is in very fine particles. So either Comet Mellish releases a very large number of small particles versus larger ones or the NOO stream has been particle size sorted by some mechanism over the past 4000-5000 years.

Obs  Date(UT)      Time    TOT SPO ANT LEO AND NOO HYD PHO PSU KDR
SAL3 2010-11-30   12h 32m   32  18  2   6   0   1   1   0   3   1
ALLS 2010-11-30   12h 32m   12  8   1   0   0   1   2   0   0   0
SAL3 2010-11-29   11h 09m   30  16  2   2   0   8   2   0   0   -
ALLS 2010-11-29   11h 24m   18  8   3   1   0   5   0   0   1   -
SAL3 2010-11-28   12h 00m   32  23  2   2   0   4   0   1   -   -
ALLS 2010-11-28   12h 10m   13  10  2   1   0   0   0   0   -   -
SAL3 2010-11-27   11h 59m   28  14  7   3   1   1   2   -   -   -
ALLS 2010-11-27   12h 14m   19  13  1   3   0   2   0   -   -   -
SAL3 2010-11-26   09h 27m   22  14  0   1   1   3   3   -   -   -
ALLS 2010-11-26   09h 42m   16  12  0   1   0   2   1   -   -   -

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   
LEO - Leonids
AND - Andromedids
NOO - November Orionids
HYD - Sigma Hydrids
PHO - Phoenicids
PSU - Psi Ursa Majorids
KDR - Kappa Draconids
 

Meteor Activity Outlook for November 27-December 3, 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 last quarter phase on Saturday November 27th. At this time the moon lies ninety degrees west of the sun and rises near midnight LST (Local Standard Time). Thus morning observers will have moonlight to contend with this weekend. Successful observations can still be undertaken as long as the moon is kept out of your field of view. The light of the last quarter moon is much less intense than that of a full moon and many meteors can still be seen, especially under transparent skies. As the week progresses the waning crescent moon becomes less of a problem as it grows dimmer and rises later and later during the early morning hours. 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. 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 November 27/28. 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 00:50 (012) -52. This position lies in central Phoenix some ten degrees southeast of the second magnitude star Ankaa (Alpha Phoenicis). These meteors are best seen near 2100 (9pm) 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.

Andromedids (AND)

Sirko Molau and Juergen Rendtel’s studies of video radiants has revealed that activity from the famous Andromedid shower, noted for intense storms during the 19th century, may still be seen throughout November. The current
position of the large radiant is 01:44 (026) +45. This position lies in eastern Andromeda, three degrees south of the fourth magnitude star 51 Andromedae. Visual activity is expected to be low, but detectable. An inconspicuous maximum occurs on November 12. The Andromedid meteors are best seen near 2200 (10pm) LST (Local Standard Time) when the radiant lies on the meridian. At 19km/sec., the average Andromedid will appear as a very slow moving meteor. Sirko mentions that these meteors are “conspicuously slow and of almost constant activity” during this period.

Northern Taurids (NTA)

The center of the large Northern Taurid (NTA) radiant lies at 04:49 (072) +25. This area of the sky is located in central Taurus, eight degrees north of the orange first magnitude star Aldebaran (Alpha Tauri). These meteors are best seen near 0100 LST, 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 05:58 (090) +15. This position lies in northeastern Orion, seven degrees north of the orange first magnitude star Betelgeuse (Alpha Orionis). These meteors are best seen near 0200 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.

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 07:52 (118) -45. This position lies in eastern Puppis, four degrees northwest 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.

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 10:38 (159) +45. This position lies in southwestern Ursa Major, five degrees west of the third magnitude star Kappa 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.

Leonids (LEO)

This week is your last chance to see the Leonids (LEO) for 2010. This shower peaked on the Thursday morning November 18 and current rates are well below 1 per hour no matter your location. The radiant is located at 10:41 (160) +19. This position lies in central Leo, four degrees east of the second magnitude star Algeiba (Gamma Leonis). The area of the sky does not clear the eastern horizon until the late evening hours so no Leonid activity can be seen during the early evening hours. These meteors are best seen during the last hour before the onset of morning twilight, when the radiant lies highest above the horizon in a dark sky. At 71km/sec., the average Leonid is swift with a high percentage of trains.

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 12:22 (185) +72. This position lies in extreme western Draco, two degrees northwest of 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    00h 50m  -52    18    <1    <1
AND Andromedids           01h 44m  +45    19    <1    <1
NTA Northern Taurids      04h 49m  +25    29     2     2
NOO November Orionids     05h 58m  +15    44     2     2
PUP Puppid-Velids         07h 52m  -45    40    <1     2
PSU Psi Ursa Majorids     19h 38m  +45    61    <1    <1
LEO Leonids               10h 41m  +19    71    <1    <1
KDR Dec Kappa Draconids   12h 22m  +72    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

Nov 11/12 to 16/17 Meteors

The maximum for this year’s Leonids shower should have taken place late this morning a few hours after sunrise here in AZ. So based on last night’s results I have only one word to describe the Leonids maximum, at least video-wise, and that word is ‘yawn!’. When the SALSA3 camera picked up 8 Leonids back on the night of Nov 11/12 I got real excited about a good display for this year. As it turned out, none of the subsequent nights really did much better. Still except during dust trail crossing years, the Leonids only produce 10-20 meteors per hour. That’s 10-20 per hour if you live under very dark skies. For most of us living in light polluted areas, rates are more like 3-8 per hour. So to be honest, I never really understand why every year there are news stories (for instance, the Leonids are on the front page of Yahoo News right now) telling the public to see what is really just a good minor shower most years. It would be much better to wait a month for a real high rate shower like December’s Geminids.

Last night marked the 53rd consecutive night with a meteor detection by the SALSA3 camera. The current forecast calls for the slight possibility of rain this weekend so we’ll see if the streak can live on.

Obs  Date(UT)      Time    TOT SPO NTA STA ORI LEO AND NOO OER AMO
SAL3 2010-11-17   11h 49m   28  15  2   2   -   7   0   0   2   0
ALLS 2010-11-17   12h 18m   22  11  1   1   -   7   0   1   1   0
SAL3 2010-11-16   11h 22m   31  13  6   3   -   5   0   1   2   1
ALLS 2010-11-16   11h 36m   21  8   1   2   -   9   0   1   0   0
SAL3 2010-11-15   06h 41m   19  8   4   2   -   4   0   1   0   0
ALLS 2010-11-15   12h 00m   13  9   0   0   0   3   0   0   1   0
SAL3 2010-11-14   11h 45m   16  11  1   1   2   0   1   0   0   -
ALLS 2010-11-14   10h 07m   5   3   1   0   1   0   0   0   0   -
SAL3 2010-11-13   12h 13m   26  18  4   1   1   1   1   0   -   -
ALLS 2010-11-13   12h 13m   16  12  3   0   0   1   0   0   -   -
SAL3 2010-11-12   11h 21m   36  16  9   1   2   8   0   0   -   -
ALLS 2010-11-12   11h 36m   28  20  3   1   1   3   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  
NTA - Northern Taurids
STA - Southern Taurids 
ORI - Orionids
LEO - Leonids
AND - Andromedids
Follow

Get every new post delivered to your Inbox.

Join 107 other followers