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 6-13, 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 new phase on Wednesday April 10th. At this time the moon is located near the sun and is not visible at night. This weekend the waning crescent moon will rise during the late morning hours but will be too thin to be much of a problem to meteor observers. 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 eight 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 April 6/7. 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 large Anthelion (ANT) radiant is currently located at 14:00 (210) -12. This position lies in southeastern Virgo, very close to the position now occupied by the zero magnitude planet Saturn. These meteors may be seen all night long but the radiant is best placed near 0200 Local Daylight Time (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.

The Zeta Cygnids (ZCY) are active from March 22 through April 10, with maximum activity occurring on the morning of April 6th. This stream was first noticed by Z. Sekanina in a study of radio meteor streams. It has been recently verified in the IMO video database producing low activity during late March and early April. The radiant is currently located near 20:00 (300) +41. This position lies in western Cygnus, four degrees west of second magnitude Sadr, (Gamma Cygni). The radiant is best placed in a dark sky just before dawn. At 45km/sec. this shower would produce meteors 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 20:08 (302) +36. This position lies in central Cygnus, three degrees northeast of the fourth magnitude star known as Eta Cygni. This position is close to that of the Zeta Cygnid radiant so care must be taken to differentiate between the two showers. No matter your location, rates at this time are expected to be less than one per hour. At 42km/sec. the Nu Cygnids would produce meteors of average velocity.

The Delta Aquiliids (DAL) are 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 20:24 (306) +11. This position actually lies in southwestern Delphinus, two degrees west of fourth magnitude star Epsilon Delphini. The radiant is best placed in a dark sky just before dawn. Rates are expected to be less than one per hour, even at maximum activity. 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 .

Anthelions (ANT) – 14:00 (210) -12   Velocity – 30km/sec.
Northern Hemisphere – 2 per hr.   Southern Hemisphere – 2 per hr

Zeta Cygnids (ZCY) – 20:00 (300) +41   Velocity – 45km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Nu Cygnids (NCY) – 20:08 (302) +36   Velocity – 42km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Delta Aquiliids (DAL) – 20:24 (306) +11   Velocity – 66km/sec.
Northern Hemisphere – <1 per hr.   Southern Hemisphere – <1 per hr

Clear Skies!
Robert Lunsford
American Meteor Society

In the Transient Sky – April 2013

April 2013 Highlights
* Comet C/2011 L4 (PANSTARRS) will be visible in the morning sky fading from magnitude 4 to 7
* Comet C/2012 F6 (Lemmon) will be a 5th-6th magnitude object for SH observers
* Saturn at opposition on the 28th
* Jupiter continues to dominate the early evening sky
* Mercury finishes a great morning apparition for southern observers (not so good for northerners)
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

Venus – Venus was in superior conjunction last month. This month the planet is still too close to the Sun for most observers. A lucky few may be able to pick it out against the bright glow of evening twilight by the end of the month.

Jupiter – The King of the Planets dominates the early evening sky being high in the western sky at the end of evening twilight. On the 1st Jupiter sets around 11:30 pm and by 10 pm at the end of the month. It spends the month a few degrees  northeast of the stars of the Hyades cluster in Taurus as it fades from magnitude -2.1 to -2.0.  The Moon pays Jupiter a visit on the evening of the 14th.

Saturn – Saturn reaches opposition this month on the 28th. On that data the ringed planet will be observable all night long. It will also be at its brightest for the year on that night at magnitude +0.1. The Moon passes close to Saturn on the morning of the 25th.

Morning Planets

Mercury – Mercury starts the month in the midst of a good morning apparition for Southern Hemisphere observers. The view is much worse for northern observers. Mercury slowly moves back towards the Sun as the month progresses.

Mars – Both planets are too close to the Sun for easy observation this month. They will be back this summer, Venus in the evening sky and Mars in the morning sky.

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 near its annual minimum 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 April mornings, 5 or so Sporadic meteors can be observed per hour from a dark moonless sky. The rate is near an annual minimum this month.

Major Meteor Showers

Lyrids [LYR]

This year’s Lyrid meteor shower is seriously hampered by a nearly Full Moon on the night of its peak (April 22nd). The Moon will greatly reduce the usual number of 10-15 meteors per hour.

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)

C/2011 L4 (PANSTARRS)

Comet PANSTARRS peaked around magnitude 1.5 when it reached perihelion at 0.30 AU from the Sun on March 10. The comet has rapidly faded as it moves away from the Earth and Sun. Observations over the past few days place is around magnitude 4.0 to 5.0.

In March it was an evening object though it spent all month hugging the western horizon and was only visible in twilight. In April the comet can still be seen in the evening with difficulty but it has become much easier to see in the morning. PANSTARRS starts the month in Andromeda only a few degrees from the Andromeda galaxy. As the month progresses it will continue moving north across Andromeda and Cassiopeia.

The comet will fade by ~1 magnitude per week but should remain a good sight in small telescopes and binoculars all month long.

Finder charts can be found at Chasing Comets.

Ephemeris for C/2011 L4 (PANSTARRS)
Date            RA        DEC    Delta   r   Elong    V
2013 Apr 01   00m 31m  +36d 33'  1.275 0.684   32    4.4
2013 Apr 11   00h 27m  +48d 13'  1.358 0.899   41    5.5
2013 Apr 21   00h 21m  +58d 12'  1.442 1.102   50    6.3
2013 May 01   00h 11m  +67d 12'  1.528 1.295   57    7.0

RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

C/2012 F6 (Lemmon)

Everyone was expecting C/2011 L4 (PANSTARRS) and C/2012 S1 (ISON) to be the two naked eye comets of 2013. No one was expecting C/2012 F6 (Lemmon) to be vying for the status of naked eye comet when it was discovered by Alex Gibbs of the Mount Lemmon survey back on March 23, 2012. At that time the comet was a faint 20th-21st magnitude and 5.0 AU from the Sun. It also appeared to be an intrinsically faint comet. So faint in fact that I though it had a good chance of disintegrating near perihelion. Instead the comet brightened at a rapid rate.

This surprise comet brightened to magnitude 4.5 to 5.0 as it reached perihelion on March 24, 2013 at a distance of 0.73 AU from the Sun. Unfortunately there have been very few brightness estimates made over the past few weeks. Not only is the comet not visible for those north of the Equator but the comet is also located only ~24 degrees from the Sun.

Lemmon should fade now that it is moving away from the Sun and Earth and may be as faint as magnitude 6-7 by month’s end. Even though it is moving nearly due north through Cetus and Pisces this month it will still not be visible to northern observers till May.

Finder charts can be found at Chasing Comets.

Ephemeris for C/2012 F6 (Lemmon)
Date            RA        DEC    Delta   r   Elong    V
2013 Apr 01   00h 11m  -17d 50'  1.547 0.746   24    4.9
2013 Apr 11   00h 12m  -08d 40'  1.622 0.810   24    5.3
2013 Apr 21   00h 14m  +00d 06'  1.671 0.910   28    5.8
2013 May 01   00h 17m  +08d 32'  1.701 1.031   34    6.4
RA = Right Ascension, DEC = Declination, Delta = distance from Earth in AU
r = distance from the Sun in AU, Elong = elongation from Sun in degrees
V = Visual magnitude

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

None