May 1-10 Meteors

The end of last month experienced the peak of the major Lyrid meteor shower. The first week or so of May is seeing some signifiant activity from the Eta Aquariids (ETA). The ETAs are actually debris from Comet Halley. They are the sister shower to October’s Orionids (ORI). So if you’ve been seeing some long bright meteors during your early morning walks the past few mornings, you’ve actually been seeing small pieces of Halley’s comet.

The IMO Live ZHR page presents reports from visual observers from all around the world. They have been observing a good shower with ZHRs of ~50. It’s too bad the radiant is only observable for an hour or so prior to sunup from the the NH.

The ETAs were predicted to peak around May 7 UT and the IMO reports confirm this. My meteor camera totals disagree as the number of ETAs has continued to climb even though we are 2-3 days past the peak. Perhaps the number of bright ETAs (which are the only ones my camera can detect) are still increasing even though the total number of meteors (bright and faint) peaked a few nights ago. Regardless, the ETAs should wind down from here on out.

2014May10_ETA

.

Obs  Date(UT)      Time    TOT SPO ANT ETA ABO PBO XLI ELY SOP
SAL  2014-05-10   08h 58m   23  11  0   11  -   -   0   1   0
SAL  2014-05-09   08h 55m   23  8   2   11  -   -   1   0   1
SAL  2014-05-08   09h 07m   17  9   1   7   -   -   0   0   0
SAL  2014-05-07   06h 16m   12  4   1   7   -   -   0   0   0
SAL  2014-05-06   09h 11m   12  3   2   7   -   -   0   0   0
SAL  2014-05-05   06h 49m   5   3   0   1   -   -   0   0   0
SAL  2014-05-04   09h 14m   16  9   2   5   0   0   0   0   0
SAL  2014-05-03   08h 42m   12  5   0   5   0   0   2   0   -
SAL  2014-05-02   08h 31m   25  14  4   5   1   0   1   -   -
SAL  2014-05-01   09h 06m   15  14  0   1   0   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 - Antihelions
ETA - Eta Aquariids
ABO - Alpha Bootids
PBO - Phi Bootids
XLI - April Chi Librids
ELY - Eta Lyrids
SOP - Southern May Ophiuchids 

Meteor Shower Activity for May 10-16, 2014

The Meteor Activity Outlook for the period 2014 February 15-21 has been posted by Bob Lunsford on the American Meteor Society website.

The Outlook has details on meteors from the Antihelion region and the following showers: Eta Aquariids (ETA), Eta Lyrids (ELY) and Theta 2 Sagittariids (TTS).

Meteor Activity Outlook for May 12-18, 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.

May is a fairly slow month for meteor activity. The Eta Aquariids are very active the first two weeks of the month then fade as the month progresses. The only other showers active this month are the weak Nu Cygnids, the Eta Lyrids,  and the Antihelion radiant. These will add only 1-2 meteors per hour to the total count. 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) are strong and remain so the entire month.

During this period the moon reaches its last quarter phase on Saturday the 12th. At this time the moon will be located ninety degrees west of the sun and will rise near 0100 local daylight time (LDT). As the week progresses the waning crescent moon will rise later in the morning, increasing the window of opportunity to view in totally dark conditions. 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 nine as seen from mid-northern latitudes and fifteen from mid-southern latitudes. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Morning rates are reduced slightly due to moonlight during this period.

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 May 12/13. 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 Antihelion (ANT) radiant is currently located at 16:16 (244) -21. This position lies in northwestern Scorpius, six degrees northwest of the bright first magnitude orange star Antares (Alpha  Scorpii). Due to the large size of this radiant, Antihelion activity may also appear from western Ophiuchus, Libra, northern Lupus, as well as Scorpius. 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 one per hour as seen from the northern hemisphere and two 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 last of the Eta Lyrids (ELY) are visible this weekend from a radiant located at 19:23 (292) +43. This position lies in extreme eastern Lyra, four degrees southwest of the third magnitude star Delta Cygni. This shower is active from May 6 through the 14th and peaked on May 11. Rates at maximum activity are near two per hour as seen from the northern hemisphere. Unfortunately the Eta Lyrid radiant does not rise very high in the northern sky as seen from the southern hemisphere so rates seen from below the equator are minimal. Activity from this shower is best seen during the last hour before dawn when the radiant is situated highest in a dark sky. With an entry velocity of 43 km/sec., the average Eta Lyrid meteor would be of medium speed.

The Eta Aquariids (ETA) are particles from Halleys 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 ZHRs of sixty. 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 30 near the equator and back down to near zero again in Antarctica, where the radiant elevation is again very low. Hourly rates this weekend will most likely be less than five per hour. Rates will slowly decrease as the week progresses as we move further from the May 7 maximum. The radiant is currently located at 22:52 (343) +01. This area of the sky is located on the Aquarius/Pisces border, three degrees east of the fourth magnitude star Eta Aquarii. The best time to view this activity is during the hour before the start of morning twilight, when the radiant lies highest in a dark sky. With the moon now in the morning eastern sky, it would be best to face either due north or due south, just enough to keep the moon out of your field of view. 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 four 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 eight 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. Morning rates are reduced due to moonlight.

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

Antihelion (ANT) – 16:16 (244) -21   Velocity 30km/sec
Northern Hemisphere – 1 per hr Southern Hemisphere – 2 per hour

Eta Lyrids (ELY) – 19:23 (292) +43   Velocity 43km/sec
Northern Hemisphere – 1 per hr Southern Hemisphere – <1 per hour

Eta Aquariids (ETA) – 22:52 (343) +01   Velocity 67km/sec
Northern Hemisphere – 3 per hr Southern Hemisphere – 5 per hour

Clear Skies!
Robert Lunsford
American Meteor Society

 

Apr 26/27 to May 15/16 Meteors

April/May/June are usually clear months in Tucson and this year is setting up to be no different. Though bouts of cirrus are common, every night but one has been clear enough to allow the detection of a few meteors.

The past few weeks have seen a couple of showers come and go. Two minor showers, the Nu Cygnids and Northern May Ophiuchids, produced only 2 meteors apiece. These showers are recent discoveries and little is known about each. The Eta Lyrids produced 1-2 meteors per night at its best. This shower is produced by the long-period Comet IRAS-Araki-Alcock which passed closer to Earth than any other observed comet over the past 200 years (5 million km in May of 1983).

The highlight of May was the Eta Aquariids. Similar to the Orionids of October, the Eta Aquariids are produced by Comet Halley. This year’s display was hampered by a bright early morning Moon but still produced healthy numbers during the last hour or 2 of each early May night.

Obs  Date(UT)      Time    TOT SPO ANT PPU NCY ETA ELY NOP
TUS  2010-05-16   08h08m    10  8   1   -   -   1   -   -
TUS  2010-05-15   01h39m    3   3   0   -   -   0   -   -
TUS  2010-05-14   05h31m    8   5   1   -   -   1   1   -
TUS  2010-05-13   05h32m    12  8   1   -   -   1   1   0
TUS  2010-05-12   08h29m    15  8   1   -   -   4   2   0
TUS  2010-05-11   08h30m    22  13  3   -   -   4   2   0
TUS  2010-05-10   08h32m    9   3   1   -   -   2   2   1
TUS  2010-05-09   08h14m    12  6   1   -   -   5   0   0
TUS  2010-05-08   04h06m    13  8   1   -   -   3   0   1
TUS  2010-05-07   08h37m    18  10  0   -   -   8   0   0
TUS  2010-05-06   04h49m    15  9   0   -   -   6   0   -
TUS  2010-05-05   08h41m    11  4   1   -   0   6   -   -
TUS  2010-05-04   08h43m    7   1   0   -   1   5   -   -
TUS  2010-05-03   07h27m    14  10  0   -   0   4   -   -
TUS  2010-05-02   07h41m    5   2   2   -   0   1   -   -
TUS  2010-05-01   08h49m    12  9   2   -   0   1   -   -
TUS  2010-04-30   00h45m    3   2   0   -   0   1   -   - 
TUS  2010-04-29   08h52m    8   4   0   -   1   3   -   -
TUS  2010-04-28   00h00m    Bad Weather
TUS  2010-04-27   00h48m    2   2   0   0   0   -   -   -

TUS - Camera in Tucson operated by Carl Hergenrother
SDG - Camera in San Diego operated by Bob Lunsford
TotTime - 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
PPU - Pi Puppids
NCY - Nu Cygnids
ETA - Eta Aquariids
ELY - Eta Lyrids
NOP - Northern May Ophiuchids

Meteor Activity Outlook for May 8-14, 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.

May is a fairly slow month for meteor activity. The Eta Aquariids are very active the first two weeks of the month then fade as the month progresses. The only other showers active this month are the weak Nu Cygnids, the Eta Lyrids, and the Antihelion radiant. These will add only 1-2 meteors per hour to the total count. 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) continue to rise this month toward a maximum in July.

During this period the moon reaches its new phase on Friday May 14th . At this time the moon lies near the sun and cannot be seen at night. This weekend the waning crescent moon will rise during the early morning hours but will not interfere with meteor observing as long as the observer keeps it out of the field of their field of view. 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 ~12 from the northern hemisphere and ~20 as seen from the southern hemisphere. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning May 8/9. These positions do not change greatly day to day so the listed coordinates may be used during this entire period.

The following showers are expected to be active this week:

Antihelions (ANT)

The wide Antihelion (ANT) radiant is now centered at 16h:04m (241) -21. This area of the sky lies in northwestern Scorpius just one degree to the southwest of the third magnitude star Acrab (Beta Scorpii). 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 Libra, northern Lupus, southern Ophiuchus, 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.

Eta Lyrids (ELY)

The Eta Lyrids (ELY) are visible this week from a radiant located at 19h:24m (291) +43. This position lies in extreme eastern Lyra, four degrees southwest of the third magnitude star Delta Cygni. This shower is active from May 6 through the 13th, peaking on May 10. Rates at maximum activity are near two per hour as seen from the northern hemisphere. Unfortunately the Eta Lyrid radiant does not rise very high in the northern sky as seen from the southern hemisphere so rates seen from below the equator are minimal. Activity from this shower is best seen during the last hour before dawn when the radiant is situated highest in a dark sky. With an entry velocity of 43 km/sec., the average Eta Lyrid meteor would be of medium speed.

Eta Aquariids (ETA)

The Eta Aquariids (ETA) are 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 sixty. 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 weekend are anywhere from zero to ten per hour depending on your latitude and observing conditions. Rates will slowly decrease as we move further away from the May 7 maximum. The radiant is currently located at 22h:40m (340) +00. This area of the sky is located in northeastern Aquarius, just one degree east of the fourth magnitude star Eta 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.

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

Shower Name                RA     DEC   Vel     Rates
                                        km/s   NH    SH
ANT Antihelions          16h 04m  -21    30     1     2
ELY Eta Lyrids           19h 24m  +43    42     2    <1
ETA Eta Aquariids        22h 40m  +00    67     5     6

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

May 9/10/11 Meteors

This is more like it. After 2+ months of very low meteor rates, May brings rates to be excited about. This is due to 3 factors. 1) The weather is great. May is in the middle of Tucson’s dry season. Though high cirrus is possible and you can’t rule out the rare rain event, it is usually hot and bone dry. Yesterday’s high was 101F and the humidity was a paltry 4%. 2) We have 2 active showers producing a few meteors per night, the Eta Aquarids and Eta Lyrids. 3) The number of background Sporadics are slowly increasing from their annual low in the Spring.

Obs  Date (UT)   TotTime TOT SPO ANT ETA ELY
TUS  2009-05-11  07h 42m  9   4   2   1   2
TUS  2009-05-10  08h 29m  15  8   2   4   1

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – 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
ETA – Eta Aquarids
ELY – Eta Lyrids

May 5/6/7/8/9 Meteors

The Eta Aquarids were predicted to peak during the evening of May 5. For observers in North America, this means the mornings of May 5 and 6 should have produced the most meteors. Interestingly, the number of Eta Aquarids being detected nightly is not much lower than the nights around the peak. This suggests the ETAs have a broad peak with maximum activity being seen over many nights. This is in contrast to showers like the Quadrantids or the Lyrids of 2 weeks ago that have narrow peaks that last for only a day. The ETA are more similar to the Orionids of October which is not surprising since both showers are produced by Comet Halley.

Though much less active than the Eta Aquarids, the Eta Lyrids are also producing a meteor or so every night or two. The minor shower is derived from Comet IRAS-Araki-Alcock, a comet which passed extremely close to the Earth in May of 1983.

Bob made a trek into the Southern California mountains to find darker skies. His results from the nights bracketing the ETA peak are included in the table below. From his notes: “Skies have been mostly cloudy at night in the San Diego area since the Lyrid maximum. In fact I had to drive to the local mountains to record any activity from the Eta Aquariids.”

Obs  Date (UT)   TotTime TOT SPO ANT ETA ELY
TUS  2009-05-09  07h 50m  15  6   0   8   1
TUS  2009-05-08  08h 29m  14  6   1   7   0
TUS  2009-05-07  08h 36m  9   4   0   3   2
SDG  2009-05-07  02h 00m  38  18  2   17  1
TUS  2009-05-06  06h 44m  9   1   0   8   0
SDG  2009-05-06  02h 00m  44  22  3   19  0

TUS – Camera in Tucson operated by Carl Hergenrother
SDG – Camera in San Diego operated by Bob Lunsford
TotTime – 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
ETA – Eta Aquarids
ELY – Eta Lyrids

Follow

Get every new post delivered to your Inbox.

Join 107 other followers