Late April Meteors

April 22 marked the peak of the Lyrid meteor shower. The Lyrids are considered a major shower though, in reality, they are the weakest of the major showers. You might even be able to call them the strongest minor shower.

The Lyrids were produced by comet C/1861 G1 (Thatcher), a comet seen only in 1861. It is a high inclination (~80º) long-period comet with a period of ~400 years. The shower is also prone to outbursts though none was predicted for or reported this year. On the April 22 UT, a total of 21 Lyrids were observed. The star chart below shows the radiant of the Lyrids halfway between Lyra and the keystone of Hercules.

2014Apr22_Lyrids

.

Obs  Date(UT)      Time    TOT SPO ANT SLE PPU LYR ETA
SAL  2014-04-30   09h 13m   16  12  1   -   -   -   3
SAL  2014-04-29   09h 23m   13  11  2   -   -   -   0
SAL  2014-04-28   09h 09m   12  10  1   -   0   -   1
SAL  2014-04-27   09h 01m   16  13  2   -   0   -   1
SAL  2014-04-26   08h 03m   6   4   0   2   0   -   0
SAL  2014-04-25   09h 07m   12  10  2   0   0   0   0
SAL  2014-04-24   08h 15m   11  8   1   0   0   2   0
SAL  2014-04-23   07h 39m   15  8   1   2   0   4   0
SAL  2014-04-22   09h 08m   30  8   1   0   0   21  0
SAL  2014-04-21   09h 12m   14  9   1   1   0   3   0
SAL  2014-04-20   07h 54m   15  13  0   1   0   1   0
SAL  2014-04-19   06h 19m   5   4   0   0   0   1   0
SAL  2014-04-18   00h 00m    "Clouds All Night"
SAL  2014-04-17   08h 23m   11  7   2   1   0   1   -
SAL  2014-04-16   09h 49m   17  13  3   1   0   0   -

SAL - SALSA3 camera in Tucson (Carl Hergenrother)
VIS - Visual observations from Tucson (Carl Hergenrother)
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 - AntihelionsZSE - Zeta Serpentids
SLE - Sigma Leonids
PPU - Pi Puppids
LYR - Lyrids
ETA - Eta Aquariids

Early April Meteors

It has been awhile since I last posted. Even though I’ve been quiet, my meteor camera has been running almost every night (though I did forget to turn it on one night :) ).

Early April continues a period of no active major showers. The period does contain many active minor showers. Though most produce little activity, the Sigma Leonids (SLE) showed a consistent level of low activity through out early and late April. The SLEs are on a low inclination Jupiter-family comet or near-Earth asteroid orbit.

My next post will present the meteors from late April when we’ll see some activity from a major shower.

Obs  Date(UT)      Time    TOT SPO ANT ZSE ZCY LVI DAL SLE PPU
SAL  2014-04-15   09h 37m   9   9   0   -   -   -   0   0   0
SAL  2014-04-14   09h 44m   14  11  2   -   -   -   0   1   -
SAL  2014-04-13   09h 21m   10  7   0   -   -   0   0   3   -
SAL  2014-04-12   00h 42m   1   1   0   -   -   0   0   0   -
SAL  2014-04-11   03h 29m   2   2   0   -   0   0   0   0   -
SAL  2014-04-10   09h 37m   8   5   2   -   0   0   1   0   -
SAL  2014-04-09   09h 27m   11  8   1   -   0   0   0   2   -
SAL  2014-04-08   09h 02m   11  9   0   -   0   1   0   1   -
SAL  2014-04-07   09h 46m   16  16  0   -   0   0   0   -   -
SAL  2014-04-06   09h 44m   13  9   3   -   1   0   0   -   -
SAL  2014-04-05   10h 02m   7   5   1   -   1   0   -   -   -
SAL  2014-04-04   09h 55m   10  5   3   -   0   2   -   -   -
SAL  2014-04-03   09h 33m   11  10  1   0   0   -   -   -   -
SAL  2014-04-02   09h 29m   14  14  0   0   0   -   -   -   -
SAL  2014-04-01   00h 00m       "FORGOT to TURN on CAMERA"

SAL - SALSA3 camera in Tucson (Carl Hergenrother)
VIS - Visual observations from Tucson (Carl Hergenrother)
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 - AntihelionsZSE - Zeta Serpentids
ZCY - Zeta Cygnids
LVI - Lambda Virginids
DAL - Delta Aquiliids
SLE - Sigma Leonids
PPU - Pi Puppids

Meteor Activity Outlook for April 20-26, 2013

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.

Meteor activity picks up a bit during April as the Lyrids become active during the month. They are active from the 18th through the 25th, with a pronounced maximum on the 22nd. Sporadic rates during April are steady as seen from both hemispheres with southern observers enjoying twice the activity that can be seen from the mid-northern hemisphere.

During this period the moon reaches its full phase on Thursday April 25th. At this time the moon is located opposite the sun and will lie above the horizon all night long. This weekend the waxing gibbous moon will set during the late morning hours and allow a very short period of dark skies for meteor observing. The estimated total hourly meteor rates for evening observers this week is near three as seen from the northern hemisphere and four as seen from south of the equator. For morning observers the estimated total hourly rates should be near seventeen no matter your location. 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 during this period due to the bright moon.

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 April 20/21. 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:

Activity from the Pi Puppids (PPU) may be seen from the southern hemisphere from a radiant located at 07:16 (109) -45. This area of the sky is located central Puppis, just southwest of the third magnitude star Sigma Puppis. This area of the sky is best seen as soon as it becomes dark during the early evening hours. No matter your location, rates are expected to be low. Observers located in the tropical northern hemisphere may also see some activity but at latitudes north of 30 degrees north, the odds are against seeing any activity at all. At 18km/sec. the Pi Puppids would produce meteors of very slow velocity.

The Sigma Leonids B (SLE) is the second of two branches of this shower. This shower was first noticed by Terentjeva (1990) in her analysis of 554 fireball orbits. This particular branch is active from April 18-26, with maximum activity occurring on the evening of the 19th. The radiant is currently located near 13:32 (203) +03. This position actually lies in central Virgo (not Leo), three degrees north of the third magnitude star Heze (Zeta Virginis). The radiant is best placed near 0100 when it lies highest above the horizon. This shower can be seen equally well from both hemispheres and may be partially responsible for the April fireballs. At 20km/sec. this shower would produce meteors of slow velocity.

The center of the large Anthelion (ANT) radiant is currently located at 14:44 (221) -16. This position lies in western Libra, just west of the third magnitude double star known as Zubenelgenubi (Alpha 2 Librae). These meteors may be seen all night long but the radiant is best placed near 0200 LDT when it lies on the meridian and is highest in the sky. Rates at this time should be near two per hour no matter your location. With an entry velocity of 30 km/sec., the average Anthelion meteor would be of slow velocity.

Activity from the Lyrid (LYR) shower reaches maximum activity on the morning of April 22th with the radiant located at 18:08 (272) +33. This area of the sky is actually located in eastern Hercules, two degrees southwest of the faint star known as Kappa Lyrae. This position also lies six degrees southwest of the brilliant zero magnitude star Vega (Alpha Lyrae). The radiant is best placed just before the break of dawn when the radiant lies highest in the sky. While Lyrid meteors can be seen in both hemispheres, the north is favored as the radiant lies much higher in the sky. Hourly rates at maximum are expected to be 10-15 shower members during the short time between moon set and dawn, when the sky is totally dark. South of the equator rates would most likely be near 5 Lyrids per hour. At 48km/sec. the Lyrids would produce meteors of medium-swift velocity.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed a weak radiant active in the constellation of Cygnus this time of year. The Nu Cygnids (NCY) are active from April 2 through May 4 with maximum activity occurring on April 18. The current radiant position lies at 20:40 (310) +43. This position lies in central Cygnus, two degrees south of the bright first magnitude star known as Deneb (Alpha Cygni). Rates are expected to be near one shower member per hour during the last couple of hours before dawn. While well placed for the northern hemisphere, this radiant is poorly seen from the southern hemisphere. At 42km/sec. the Nu Cygnids would produce meteors of average velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near one per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near ten 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 bright moonlight.

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

Pi Puppids (PPU) – 07:16 (109) -45   Velocity – 18km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Sigma Leonids B (SLE) – 13:32 (203) +03   Velocity – 20km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 2 per hr

Anthelions (ANT) – 14:44 (221) -16   Velocity – 30km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 2 per hr

Lyrids (LYR) – 18:08 (272) +33   Velocity – 48km/sec.
Northern Hemisphere – 10 per hr.   Southern Hemisphere – 5 per hr

Nu Cygnids (NCY) – 20:40 (310) +43   Velocity – 42km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Clear Skies!
Robert Lunsford
American Meteor Society

Meteor Activity Outlook for April 13-19, 2013

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.

Meteor activity picks up a bit during April as the Lyrids become active during the month. They are active from the 18th through the 25th, with a pronounced maximum on the 22nd. Sporadic rates during April are steady as seen from both hemispheres with southern observers enjoying twice the activity that can be seen from the mid-northern hemisphere.

During this period the moon reaches its first quarter phase on Wednesday April 17th. At this time the moon is located ninety degrees east of the sun and sets near 0100 local daylight time (LDT). This weekend the waxing crescent moon will set during the late evening hours and will not cause any problems for meteor observing. The estimated total hourly meteor rates for evening observers this week is near three as seen from the northern hemisphere and four as seen from south of the equator. For morning observers the estimated total hourly rates should be near ten from the mid-northern hemisphere and fifteen 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 April 13/14. 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:

Activity from the Pi Puppids (PPU) begins this week from a radiant located at 07:04 (106) -44. This area of the sky is located central Puppis, five degrees southwest of the third magnitude star Sigma Puppis. This area of the sky is best seen as soon as it becomes dark during the early evening hours. No matter your location, rates will be low, far less than one per hour this early in the activity curve. Observers located in the southern hemisphere have a much better view of this activity as the radiant lies higher in their evening sky. At 18km/sec. the Pi Puppids would produce meteors of very slow velocity.

The Sigma Leonids A (SLE) is the first of two branches of this shower. This shower was first noticed by Terentjeva (1990) in her analysis of 554 fireball orbits. This particular branch is active from April 8-16, with maximum activity occurring on the evening of the 10th. The radiant is currently located near 13:20 (200) +04. This position actually lies in central Virgo (not Leo), five degrees east of the third magnitude star Auva (Delta Virginis). The radiant is best placed near 0100 when it lies highest above the horizon. This shower is currently the strongest in the sky, producing an average of two shower members per hour while the radiant is high in the sky. This shower can be seen equally well from both hemispheres and may be partially responsible for the April fireballs. At 22km/sec. this shower would produce meteors of slow velocity.

The second branch (B) of the Sigma Leonids (SLE) becomes active on April 18th and lasts until the 26th. Maximum activity is not until April 20th. On the 18th, the position of this radiant lies at 13:28 (202) +07, which also places it central Virgo, seven degrees northeast of the third magnitude star Auva (Delta Virginis). The radiant is best placed near 0100 when it lies highest above the horizon. At 20km/sec. this shower would produce meteors of slow velocity.

The large Anthelion (ANT) radiant is currently located at 14:28 (217) -15. This position lies in western Libra, five degrees west  of the third magnitude double star known as Zubenelgenubi (Alpha 2 Librae). These meteors may be seen all night long but the radiant is best placed near 0200 LDT when it lies on the meridian and is highest in the sky. Rates at this time should be near two per hour no matter your location. With an entry velocity of 30 km/sec., the average Anthelion meteor would be of slow velocity.

Activity from the Lyrid (LYR) shower is first detectable on April 18th and the shower reaches maximum activity four nights later. On the 18th the radiant is located at 18:00 (270) +35. This area of the sky is actually located in eastern Hercules, two degrees southeast of the faint star known as Theta Herculis. This position also lies eight degrees southwest of the brilliant zero magnitude star Vega (Alpha Lyrae). The radiant is best placed just before the break of dawn when the radiant lies highest in the sky. While Lyrid meteors can be seen in both hemispheres, the north is favored as the radiant lies much higher in the sky. Rates this early in the activity curve would be low, less than one per hour no matter your location. At 48km/sec. the Lyrids would produce meteors of medium-swift velocity.

Juergen Rendtel and Sirko Molau have discovered an previously unknown radiant active this time of year on the Lyra-Cygnus border. IMO shower #59 is active from April 13-19 with maximum activity occurring on the 16th. The position at maximum activity lies at 19:27 (292) +37, which places it on the Lyra-Cygnus border, only three degrees southeast of the twin fourth magnitude stars Eta and Theta Lyrae. Rates, even at maximum activity, is expected to be less that one per hour no matter your location. With an entry velocity of 45 km/sec., the average meteor from this shower would be of medium velocity.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed a weak radiant active in the constellation of Cygnus this time of year. The Nu Cygnids (NCY) are active from April 2 through May 4 with maximum activity occurring on April 18. The current radiant position lies at 20:28 (307) +38. This position lies in central Cygnus, two degrees south of the second magnitude star known as Sadr (Gamma Cygni).  At maximum, rates are expected to be near one shower member per hour during the last couple of hours before dawn. While well placed for the northern hemisphere, this radiant is poorly seen from the southern hemisphere. At 42km/sec. the Nu Cygnids would produce meteors of average velocity.

The last of the Delta Aquiliids (DAL) can be seen this weekend. This weak shower is active from April 5 through through the 13th, with maximum activity occurring on the morning of 11th. This stream was first noticed by Peter Jenniskens and is mentioned in his book Meteor Showers and their Parent Comets. It has been recently verified in the IMO video database producing low activity during the period mentioned above. The radiant is currently located near 20:48 (312) +14. This position actually lies in central Delphinus, two degrees south of fourth magnitude double star Gamma Delphini. The radiant is best placed in a dark sky just before dawn. Rates are expected to be less than one per hour and is seen equally well from both hemispheres. At 66km/sec. this shower would produce meteors of swift velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five 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 ten per hour as seen from rural observing sites and three per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

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

Pi Puppids (PPU) – 07:04 (106) -44   Velocity – 18km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Sigma Leonids A (SLE) – 13:20 (200) +04   Velocity – 22km/sec.
Northern Hemisphere – 2 per hr. Southern Hemisphere – 2 per hr

Sigma Leonids B (SLE) – 13:28 (202) +07   Velocity – 20km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 2 per hr

Anthelions (ANT) – 14:28 (217) -15   Velocity – 30km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 2 per hr

Lyrids (LYR) – 18:00 (270) +35   Velocity – 48km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

IMO #59 – 19:27 (292) +37   Velocity – 45km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Nu Cygnids (NCY) – 20:28 (307) +38   Velocity – 42km/sec.
Northern Hemisphere – <1 per hr. Southern Hemisphere – <1 per hr

Delta Aquiliids (DAL) – 20:48 (312) +14   Velocity – 66km/sec.
Northern Hemisphere – <1 per hr. Southern Hemisphere – <1 per hr

Clear Skies!
Robert Lunsford
American Meteor Society

Meteor Activity Outlook for April 21-27, 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.

Meteor activity picks up a bit during April as two major showers are active during the month. The first of these, the Lyrids, are active from the 16th through the 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start appearing near the 28th and reach maximum activity during the first week in May. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) rise this month toward a maximum in July.

During this period the moon reaches its new phase on Saturday the 21st. At this time the moon will be near the sun and will not be visible at night. This will be the best time of the month in which to view meteor activity.  As the week progresses the waxing crescent moon will enter the evening sky but will not be bright enough to interfere with observing. In addition the moon will set during the evening hours allowing the more active morning to be free from any interfering moonlight.  The estimated total hourly rates for evening observers this week is near three for observers in the northern hemisphere and four for those south of the equator. For morning observers the estimated total hourly rates should be near twenty-three as seen from mid-northern latitudes and nineteen 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.

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 April 21/22. 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:

Activity from the Pi Puppids (PPU) continues this week from a radiant located at 07:16 (109) -45. This area of the sky is located central Puppis, two degrees southwest of the third magnitude star Sigma Puppis. This area of the sky is best seen as soon as it becomes dark during the early evening hours. Maximum activity is predicted to occur on Sunday evening the 22nd (23rd UT). Despite this, rates less than one per hour are expected, no matter your location. Observers located in the southern hemisphere have a much better view of this activity as the radiant lies higher in the sky. At 18km/sec. the Pi Puppids would produce meteors of very slow velocity.

The weak shower known as the Sigma Leonids (SLE) is active from a radiant located at 13:40 (205) +04, which actually lies in northern Virgo, four degrees northeast of the third magnitude star Zeta Virginis. One might feel this shower was named for the wrong constellation, but the case is more likely that visual observations, made before the advent of video methods, placed the radiant incorrectly further westward in Leo. This radiant is best placed near 0300 local daylight time (LDT), when it lies on the meridian and is located highest in the sky. Rates at this time would be less than one per hour no matter your location. With an entry velocity of 20 km/sec., the average Sigma Leonid meteor would be of very slow velocity.

There is also another radiant active in Virgo this time of year. Video data from The IMO shows that the h Virginids (HVR) are active from April 22-25 with maximum activity occurring on the 22nd. On the evening of the 21st (22nd UT), the radiant is located at 14:16 (214) -11. This position lies on the Virgo/Libra border, two degrees southeast of the fourth magnitude star Kappa Virginis. The radiant is best placed near 0200 LDT, when it lies on the meridian and is highest above the horizon. At 24km/sec. the h Virginids would produce more slow meteors. Expected rates would also be less than one per hour no matter the date or your location.

The large Antihelion (ANT) radiant is currently located at 14:56 (224) -16. This position lies in western Libra, only one degree southeast of the third magnitude star Zubenelgenubi (Alpha Librae). Due to the large size of this radiant, Antihelion activity may also appear from extreme eastern Hydra, eastern Virgo, northwestern Scorpius, as well as Libra. This radiant is best placed near 0200 LDT, 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 three as seen from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of slow velocity.

The Lyrid (LYR) shower is expected to reach maximum activity on the night of April 21/22 with rates up to 15 shower members per hour. The radiant is located at 18:08 (272) +33. This area of the sky is actually located in extreme eastern Hercules, eight degrees southwest of the brilliant blue-white star Vega (Alpha Lyrae). The radiant is best placed just before the break of dawn when the radiant lies highest in the sky. While Lyrid meteors can be seen in both hemispheres, the north is favored as the radiant lies much higher in the sky. Rates will fall rapidly after maximum and little activity will be seen the remainder of the week. At 48km/sec. the Lyrids would produce meteors of medium-swift velocity. It should be noted that the Lyrids can occasionally produce bright meteors of fireball class magnitude.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed a weak radiant active in the constellation of Cygnus this time of year. The Nu Cygnids (NCY) are active from April 18 through May 7 with maximum activity occurring on April 19. The current radiant position lies at 20:44 (311) +42. This position lies in central Cygnus, two degrees south of the first magnitude star Deneb (Alpha Cygni). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. Due to the northern declination of the radiant, this activity is not well seen from the southern hemisphere. No matter your location, rates are expected to be less than one per hour. At 42km/sec. the Nu Cygnids would produce meteors of average velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately five 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 ten per hour as seen from rural observing sites and three per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.

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

Pi Puppids (PPU) – 07:16 (109) -45   Velocity 18km/sec
Northern Hemisphere – <1 per hr Southern Hemisphere – <1 per hour

Sigma Leonids (SLE) – 13:40 (205) +04   Velocity 20km/sec
Northern Hemisphere – <1 per hr   Southern Hemisphere – <1 per hour

h Virginids (HVR) – 14:16 (214) -11   Velocity 24km/sec
Northern Hemisphere – <1 per hr   Southern Hemisphere – <1 per hour

Antihelion (ANT) – 14:56 (224) -16   Velocity 30km/sec
Northern Hemisphere – 2 per hr   Southern Hemisphere – 3 per hour

Lyrids (LYR) – 18:08 (272) +33   Velocity 48km/sec
Northern Hemisphere – 15 per hr   Southern Hemisphere – 5 per hour

Nu Cygnids (NCY) – 20:44 (311) +42   Velocity 42km/sec
Northern Hemisphere – <1 per hr   Southern Hemisphere – <1 per hour

Clear Skies!
Robert Lunsford
American Meteor Society

 

Meteor Activity Outlook for April 23-29, 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.

Meteor activity picks up a bit during April as two major showers are active during the month. The first of these, the Lyrids, are active from the 16th through the 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start appearing near the 28th and reach maximum activity during the first week in May. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) rise this month toward a maximum in July.

During this period the moon reaches its last quarter phase on Monday April 25. At this time the moon will lie ninety degrees east of the sun and will rise near 0100 LDT (Local Daylight Time) for those situated in the mid-northern latitudes. While the moonlight will cause interference for meteor observing, the effects will be much less than when the moon is near its full phase. The estimated total hourly rates for evening observers this week is near two 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 nine from the northern hemisphere and twelve as seen from south of the equator. 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 April 23/24. 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 elusive Pi Puppids (PPU) are now active from a radiant located at 07:20 (110) -45. This area of the sky lies in south-central Puppis near the third magnitude star Sigma Puppis. This radiant is best placed as soon as it becomes dark as it culminates during the afternoon hours when the sun is still above the horizon. These meteors are nearly non-existent away from the night of April 24th. Even on that night it would be lucky to spot just one, especially from the northern hemisphere, where the radiant lies low in the southwest at dusk. This shower has produced outbursts in the past so it should be monitored whenever possible, especially from the southern hemisphere. With an entry velocity of only 18 km/sec., the average Pi Puppid meteor would crawl through the sky at a snails pace.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has revealed a weak radiant active at this time in the constellation of Virgo. Video data shows that the Sigma Leonids (SLE) are active from April 18th through the 25th with maximum activity falling on the 21st. The radiant is currently located at 13:46 (207) +04. This position lies in eastern Virgo, five degrees northwest of the fourth magnitude star Tau Virginis. The radiant is best placed near midnight LDT, when it lies highest above the horizon. At 20km/sec. the Sigma Leonids would produce obvious, slow meteors. Expected rates are less than one per hour no matter your location.

There is also a second new radiant active in Virgo this time of year. Video data shows that the h Virginids (HVR) are active from April 22-25 with maximum activity occurring on the 22nd. On the evening of the 21st (22nd UT), the radiant is located at 14:16 (214) -11. This position lies on the Virgo/Libra border, two degrees southeast of the fourth magnitude star Kappa Virginis. The radiant is best placed near 0200 LDT, when it lies on the meridian and is highest above the horizon. At 24km/sec. the h Virginids would produce more slow meteors. Expected rates would also be less than one per hour no matter your location.

The wide Antihelion (ANT) radiant is now centered at 15:04 (226) -18. This area of the sky lies in central Libra, four degrees southeast of the third magnitude star Zubenelgenubi (Alpha Librae). This radiant is best placed near 0200 LDT when it lies on the meridian and is located highest in the sky. Due to the large size of this radiant, any meteor radiating from Libra, extreme eastern Hydra, northern Lupus, or western Scorpius could be a candidate for this shower. Rates at this time should be near one per hour as seen from the northern hemisphere and two per hour as seen from south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed.

The major shower known as the Lyrids (LYR) are active from April 16th through the 25th. Maximum activity occurs on the 23rd. The radiant is currently located at 18:13 (273) +32. This position lies on Hercules/Lyra border, nine degrees southwest of the brilliant blue-white zero magnitude magnitude star known as Vega (Alpha Lyrae). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon. At 48km/sec. the Lyrids would produce meteors of medium velocity. Expected rates this weekend are near two per hour during the last dark hour before dawn. Due to the northerly declination of the radiant, these meteors are not well seen from high southern latitudes.

The team of Sirko Molau and Juergen Rendtel have a third weak radiant active at this time in the constellation of Cygnus. Video data shows that the Nu Cygnids (NCY) are active from April 18th through May 7th. Maximum activity occurred on the morning of April 20th. The radiant is currently located at 20:50 (312) +42. This position lies in central Cygnus, three degrees south of the first magnitude star Deneb (Alpha Cygni). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. At 42km/sec. the Nu Cygnids would produce meteors of medium velocity. Expected rates are near one per hour during the last dark hour before dawn. Due to the northerly declination of the radiant, these meteors are not well seen from south of the equator.

Activity from the Eta Aquariids (ETA) may be seen late next week. This major shower is active from April 28 through May 21. This shower is caused by particles from Halley’s Comet, produced in Earth-crossing orbits many centuries ago. We pass closest to these orbits from May 5 through the 9th. During this period the Eta Aquariids are at their best, capable of producing ZHR’s of seventy. The actual visible rates are most often less than half this figure due to the low altitude of the radiant at dawn. Observed hourly rates at maximum normally vary from zero at 60 degrees north latitude to 25 near the equator and back down to near zero again in Antarctica, where the radiant elevation is very low. Hourly rates this week are anywhere from zero to two per hour depending on your latitude and observing conditions. Rates will increase significantly as we approach the May 7 maximum. On April 28, the radiant will be located at 22:12 (333) -04. This area of the sky is located in northern Aquarius, three degrees southwest of the fourth magnitude star Gamma Aquarii. The best time to view this activity is just before the start of morning twilight, when the radiant lies highest in a dark sky. No matter your location these meteors will appear from the eastern sky and shoot in all directions. If the radiant has sufficient altitude Eta Aquariid meteors can also be seen shooting down toward the eastern horizon. With an entry velocity of 67 kilometers per second, a majority of these meteors will appear to move swiftly with a high percentage of the bright meteors leaving persistent trains. Surprisingly, this shower produces very few fireballs.

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 one per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near fourteen 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.

Shower Name                 RA     DEC   Vel     Rates
                                         km/s   NH    SH
PPU Pi Puppids            07h 20m  -45    18    <1    <1
SLE Sigma Leonids         13h 46m  +04    20    <1    <1
HVR h Virginids           14h 16m  -11    24    <1    <1
ANT Antihelions           15h 04m  -18    30     1     2
LYR Lyrids                18h 13m  +32    48     2    <1
NCY Nu Cygnids            20h 50m  +42    42    <1    <1
ETA Eta Aquariids         22h 12m  -04    67    <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 April 16-22, 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.

Meteor activity picks up a bit during April as two major showers are active during the month. The first of these, the Lyrids, are active from the 16th through the 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start appearing near the 28th and reach maximum activity during the first week in May. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) rise this month toward a maximum in July.

During this period the moon reaches its full phase on Monday April 18. At this time the moon will lie opposite the sun and will be in the sky all night long. This is the worst time of the month to try and 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 near one 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 six from the northern hemisphere and seven as seen from south of the equator. 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 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 April 16/17. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

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
PPU Pi Puppids            07h 06m  -44    18    <1    <1
SLE Sigma Leonids         13h 18m  +06    20    <1    <1
ANT Antihelions           14h 40m  -15    30     1     1
LYR Lyrids                17h 56m  +35    48     1    <1
ZCY Zeta Cygnids          20h 00m  +37    42    <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 April 17-23, 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.

Meteor activity picks up a bit during April as two major showers are active during the month. The first of these, the Lyrids, are active from the 16th through the 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start appearing near the 28th and reach maximum activity during the first week in May. Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern hemisphere (45 S) rise this month toward a maximum in July.

During this period the moon reaches its first quarter phase on Wednesday April21st . At this time the moon lies ninety degrees east of the sun and sets near 0100 local daylight time (LDT), depending on your location. This weekend the waxing crescent moon will set shortly after the end of evening twilight and will not cause any inteference to meteor observers. The estimated total hourly rates for evening observers this week is ~2 for those in the northern hemisphere and ~3 for those south of the equator. For morning observers the estimated total hourly rates should be ~10 from the northern hemisphere and ~15 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 positions and rates listed below are exact for Saturday night/Sunday morning April 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 week:

Pi Puppids (PPU)

The elusive Pi Puppids (PPU) are now active from a radiant located at 07:12 (108) -46. This area of the sky lies in western Puppis near the double star Iota Puppi. This radiant is best placed as soon as it becomes dark as it culminates during the afternoon hours when the sun is still above the horizon. These meteors are nearly non-existent away from the night of April 23rd. Even on that night it would be lucky to spot just one, especially from the northern hemisphere, where the radiant lies low in the southwest at dusk. This shower has produced outbursts in the past so it should be monitored whenever possible, especially from the southern hemisphere. With an entry velocity of only 18 km/sec., the average Pi Puppid meteor would crawl through the sky at a snails pace.

Sigma Leonids (SLE)

The team of Sirko Molau and Juergen Rendtel have discovered a weak radiant active at this time in the constellation of Virgo. Video data shows that the Sigma Leonids (SLE) are active from April 18th through the 25th with maximum activity falling on the evening of April 21st (22nd UT). The radiant is currently located at 13:16 (199) +05. This position lies in central Virgo, five degrees northeast of the third magnitude star Delta Virginis. The radiant is best placed near midnight LDT, when it lies highest above the horizon. At 20km/sec. the Sigma Leonids would produce obvious, slow meteors. Expected rates are less than one per hour no matter your location.

h Virginids (HVR)

There is also a second new radiant active in Virgo this time of year. Video data shows that the h Virginids (HVR) are active from April 22-25 with maximum activity occurring on the 22nd. On the evening of the 21st (22nd UT), the radiant is currently located at 14:16 (220) -16. This position lies on the Virgo/Libra border, two degrees southeast of the fourth magnitude star Kappa Virginis. The radiant is best placed near 0200 LDT, when it lies on the meridian and is highest above the horizon. At 24km/sec. the h Virginids would produce more obvious, slow meteors. Expected rates would also be less than one per hour no matter your location.

Antihelions (ANT)

The wide Antihelion (ANT) radiant is now centered at 14:40 (214) -13. This area of the sky lies in western Libra, three degrees west of the second magnitude star Zubenelgenubi (Alpha Librae). This radiant is best placed near 0200 local daylight time (LDT) when it lies on the meridian and is located highest in the sky. Due to the large size of this radiant, any meteor radiating from eastern Hydra, Libra, or eastern Virgo could be a candidate for this shower. Rates at this time should be near two per hour no matter your location. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed.

Lyrids (LYR)

The major shower known as the Lyrids (LYR) are active from April 16th through the 25th. Maximum activity occurs on the morning of April 22th. The radiant is currently located at 18:00 (270) +35. This position actually lies in eastern Hercules, eight degrees southwest of the brilliant blue-white zero magnitude magnitude star known as Vega (Alpha Lyrae). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon. At 48km/sec. the Lyrids would produce meteors of medium velocity. Expected rates this weekend are near one per hour during the last dark hour before dawn. At maximum, hourly rate between 10-20 can be expected. Due to the northerly declination of the radiant, these meteors are not well seen from high southern latitudes.

Nu Cygnids (NCY)

The team of Sirko Molau and Juergen Rendtel have a third weak radiant active at this time in the constellation of Cygnus. Video data shows that the Nu Cygnids (NCY) are active from April 18th through May 7th. Maximum activity occurs on the morning of April 20th. The radiant is currently located at 20:08 (302) +38. This position lies in central Cygnus, four degrees southwest of the second magnitude star Sadr (Gamma Cygni). The radiant is best placed during the last dark hour before dawn, when it lies highest above the horizon in a dark sky. At 42km/sec. the Nu Cygnids would produce meteors of medium velocity. Expected rates are near one per hour during the last dark hour before dawn. Due to the northerly declination of the
radiant, these meteors are not well seen from south of the equator.

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
PPU Pi Puppids           07h 12m  -46    18    <1    <1
SLE Sigma Leonids        13h 16m  +05    20    <1    <1
HVR h Virginids          14h 16m  -11    24    <1    <1
ANT Antihelions          14h 40m  -16    30     1     2
LYR Lyrids               18h 00m  +35    48     1    <1
NCY Nu Cygnids           20h 08m  +38    42     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 104 other followers