Oct 27/28 Meteors

For the 2nd night in a row, enhanced activity from the Beta Cancrids has been observed. Note, that any obvious activity from the Beta Cancrids can be classified as enhanced due to its usually very low rates. Two nights ago, 8 Beta Cancrids were seen over Tucson with only a single one over San Diego. Last night, 5 were seen over San Diego. We’ll never know how many were over Tucson due to the clouds.

From Bob’s notes : “After a cloudy day and even some sprinkles, the sky began to clear near dusk. During the evening hours there were still lots of cirrus and occasional cumulus clouds floating by. I decided to hold off recording to see if the sky improved. At midnight the sky was still sub par. At 3:15am I woke to totally clear skies and no moon. The ran the camera the remainder of the morning and managed to record 44 meteors in just under 3 hours. The Beta Cancrids were surprisingly active with 5 shower member recorded.”

Obs Date (UT)  TotTime TOT SPO NTA STA ORI BCN ETT LMI
TUS 2009-10-28 00h 00m  Clouds all night long
SDG 2009-10-28 02h 52m  44  18  2   3   15  5   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)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
ORI – Orionids
OUI – October Ursae Minorids
BCN – Beta Cancrids
LMI – Leonis Minorids

Oct 26/27 Meteors

Last night may be the last clear night for a while as a strong (but dry :() storm system sweeps through the desert southwest.

Meteor rates are still well above average. Even though we are a few days removed from the peak of the Orionids, they are still producing a good number of meteors. It is interesting to note that my system picked up ~8 possible members of the Beta Cancrids but Bob’s only saw a single possible member. The Beta Cancrids are a weak shower that has not been well characterized. With a velocity of 66 km/s, the shower was created by a long-period comet in a retrograde orbit.

Bob’s notes for the past 2 nights : “High clouds interfered with observing tonight. The waxing gibbous moon is also becoming a factor as it remains in the sky more of the night.”

Obs Date(UT)TotTime TOT SPO NTA STA ORI BCN ETT EGE LMI
TUS Oct-27  07h 59m  84  27  3   3   36  8   2   3   2
SDG Oct-27  10h 56m  61  25  6   5   20  1   2   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)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
ORI – Orionids
OUI – October Ursae Minorids
BCN – Beta Cancrids
EGE – Epsilon Geminids
LMI – Leonis Minorids

Oct 24/25/26 Meteors

After peaking in intensity last week, the Orionids are slowly winding down for 2009. Rates are about half to a third of what they were at the peak. This is true for both video observers and visual observers.

Bob’s notes for the past 2 nights : “Listed below is data from the past 3 nights obtained from home. On the 24th skies clouded up after only 2 hours of observing. The remaining two nights were mostly clear except for some scattered cirrus.”

Obs Date(UT)TotTime TOT SPO NTA STA ORI OUI ETT EGE LMI
TUS Oct-26  11h 19m  93  35  4   1   47  0   1   0   5
SDG Oct-26  10h 43m  83  29  2   2   43  0   -   2   1
TUS Oct-25  07h 37m  38  13  3   4   16  1   1   0   0
SDG Oct-25  10h 09m 123  31  7   9   64  1   -   9   2

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)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
ORI – Orionids
OUI – October Ursae Minorids
ETT – Eta Taurids
EGE – Epsilon Geminids
LMI – Leonis Minorids

Meteor Activity Outlook for October 24-30, 2009

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 in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with several minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 22nd. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere this time of year.

During this period the moon reaches its first quarter phase on Monday October 26th. On that date the moon lies ninety degrees east of the sun and sets near 0100 local daylight time (LDT), depending on your location. As the week progresses the waxing gibbous moon sets later in the morning, lessening the window of opportunity to view meteor activity in a dark sky. The estimated total hourly rates for evening observers this week is ~5 as seen from the northern hemisphere and ~2 from the southern hemisphere. For morning observers the estimated total hourly rates should be ~25 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. Evening rates are reduced by moonlight.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning October 24/25. 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.

October Ursa Minorids (OUI)

A new radiant has been discovered in Ursa Minor which is active during this period. The October Ursa Minorids (OUI) are active from October 16-28, with maximum occurring on the 24th. The current radiant position lies at 18:09 (272) +74. This position lies in eastern Draco near the faint star Chi Draconis. The radiant is best placed just as soon as it becomes dark, when it lies highest in a dark sky. Meteors from the October Ursa Minorids strike the atmosphere at 28km/sec., which would produce meteors of slow velocity. Expected rates would be < 1 per hour, as seen from the northern hemisphere. Activity from this shower is not visible in the southern hemisphere due to the high northerly location of the radiant.

Northern Taurids (NTA)

The Northern Taurids (NTA) are active from a large radiant centered at 02:52 (043) +20, which lies in central Aries, five degrees west of the fourth magnitude star Delta Arietis. The radiant is best placed near 0200 LDT, when it lies highest above the horizon. Meteors from the Northern Taurids strike the atmosphere at 29km/sec., which would produce meteors of slow velocity. Expected rates would be ~1 per hour, no matter your location.

Southern Taurids (STA)

The center of the large Southern Taurid (STA) radiant lies at 02:58 (044) +11. This position lies on the Aries/Cetus border, three degrees east of the fourth magnitude star Mu Ceti. The radiant is best placed near the meridian at 0200 LDT, but activity may be seen all night long. Striking the atmosphere at 29 km/sec., the average Southern Taurid meteor travels slowly through the skies. Rates should be ~2 per hour no matter your location.

Eta Taurids (ETT)

A new radiant has been discovered in Taurus which is active during this period. The Eta Taurids (ETT) are active from October 25 through November 3, with maximum occurring on the 25th. The current radiant position lies at 03:42 (056) +24, which lies in western Taurus in the area of sky occupied by the famous Pleiades star cluster. The radiant is best placed near 0300 LDT, when it lies highest above the horizon. Meteors from the Eta Taurids strike the atmosphere at 47km/sec., which would produce meteors of average  velocity. Expected rates would be < 1 per hour, no matter your location.

Orionids (ORI)

The Orionids (ORI) reached maximum activity on the nights of October 21 and 22. Rates are now falling and will do so until the last Orionids are seen near November 14. The radiant is currently located at 06:34 (98) +16. This position lies in western Gemini very close to the second magnitude star Alhena (Gamma Geminorum). The radiant is best placed near 0530 LDT, when it lies highest above the horizon. Current rates would be ~5 per hour. At 66km/sec., the average Orionid is swift.

Epsilon Geminids (EGE)

The Epsilon Geminids (EGE) are active from October 16th through the 27th. Maximum activity occurred on the 19th. The radiant is currently located at 07:09 (107) +27. This position lies in central Gemini, three degrees south of the fourth magnitude star Tau Geminorum. This position is also close to the Orionid radiant so care must taken for correct shower association, especially since they have similar velocities. The Orionids will be more numerous. Current rates are most likely less than one per hour. The radiant is best placed near 0600 LDT, when it lies highest above the horizon. At 70km/sec., the average Epsilon Geminid is swift.

Beta Cancrids (BCN)

Recent studies by Sirko Molau has revealed a radiant in Cancer that is active this time of year. The Beta Cancrids (BCN) are active from October 25 through November 3, with maximum occurring on the 27th. The current radiant position lies at 07:16 (109) -09, which lies in southwestern Canis Minor, seven degrees southwest of the brilliant zero magnitude star Procyon (Alpha Canis Minoris. The radiant is best placed near 0600 LDT, when it lies highest above the horizon.Meteors from the Beta Cancrids strike the atmosphere at 65km/sec., which would produce meteors of swift velocity. Expected rates would be < 1 per hour, no matter your location.

Leonis Minorids (LMI)

The Leonis Minorids (LMI) are active from October 16-27 with maximum activity occurring on October 23rd. ZHR’s are usually low but the radiant is far removed from the Orionids and Epsilon Geminids so that any possible shower members should be easily identified. Hourly rates should be near one this weekend. This radiant is currently located at 10:52 (163) +36, which places it in northeastern Leo Minor, just northwest of the fourth magnitude star 46 Leonis Minoris. The radiant is best placed just before dawn when it lies highest in a dark sky. This shower is better situated for observers situated in the northern hemisphere where the radiant rises far higher into the sky before the start of morning twilight. At 60km/sec., the average Leonis Minorid is swift.

As seen from the mid-northern hemisphere (45N) one would expect to see ~16 Sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near ~3 per hour. As seen from the mid-southern hemisphere (45S), morning rates would be near ~5 per hour as seen from rural observing sites and ~1 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Rates are reduced during the morning hours 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 except for showers of short duration, when the position on the night of maximum is listed.

Shower Name               RA   DEC Vel    Rates
                                   km/s  NH   SH
OUI Oct Ursa Minorids   18h09m +74  28    1    1
NTA Northern Taurids    02h52m +20  29   <1   <1
STA Southern Taurids    02h58m +11  29    2    2
ETT Eta Taurids         03h42m +24  47   <1   <1
ORI Orionids            06h34m +16  67    5    5
EGE Epsilon Geminids    06h44m +28  70   <1   <1
BCN Beta Cancrids       07h16m -09  65   <1   <1
LMI Leonis Minorids     10h52m +36  60   <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

Oct 23/24 Meteors

In yesterday’s post, I mentioned that I expected the rate of Orionids to start falling last night. It didn’t happen. Though rates have slightly decreased when compared with the previous 3 nights, the Orionids were still near their maximum for an amazing 5th straight night. Visual reports to the IMO’s real-time page confirm the continued elevated rates with activity varying between a ZHR of 25 and 45 meteors per hour.

Orionid_activity

Obs Date(UT)TotTime TOT SPO NTA STA ORI OUI SSA EGE LMI
TUS Oct-24  10h 46m 154  38  4   3   99  1   1   3   5
SDG Oct-24  02h 00m  4   4   0   0   0   0   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)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
ORI – Orionids
OUI – October Ursae Minorids
SSA – Sigma Arietids
EGE – Epsilon Geminids
LMI – Leonis Minorids

Oct 22/23 Meteors

Orionid activity has not let up at all. Last night’s rates are comparable to the past 3 nights. The graph below presents the number of Orionids my 2 camera SALSA system detected throughout each night. Though there may have been sky brightness and transparency difference from night-to-night, the nights were clear when the Orionid radiant was above the horizon allowing for a realistic measurement of the night-to-night variability in activity. [Note, there were  clouds on the 19th so its numbers are probably too low.]

Orionids_activity

Visual reports to the IMO’s real-time page, still show activity varying between a ZHR of 25 and 45 meteors per hour. Some of the variation is undoubtably due to different observers and observing conditions, but some of the variation may also be real as the Earth encounters dust streams of different intensities. Rates should start falling by tonight.

Bob’s report from the Mojave : “My last night from the Mojave Desert was plagued by cirrus clouds and equipment problems. Dead batteries limited my video recording to only two hours. Luckily this two hour period was cloud free.”

Obs Date(UT)TotTime TOT SPO NTA STA ORI OUI SSA EGE LMI
TUS Oct-23  06h 43m 142  27  3   1  106  1   1   0   3
SDG Oct-23  02h 00m  88  17  1   2   60  0   -   2   6

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)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
ORI – Orionids
ZTA – Zeta Taurids
OUI – October Ursae Minorids
SSA – Sigma Arietids
EGE – Epsilon Geminids
LMI – Leonis Minorids

Oct 21/22 Meteors

The Orionids were still going strong last night. For the 2nd night in a row, my cameras pick up 113 Orionids. Based on the IMO’s real time activity plot, ZHR rates have ranged between 20 and 50 for the past 3 nights.  Rates should start to fall from here on out. Still observers should be able to pick up 15-30 meteors per hour from dark sites tonight.

Bob’s report from the Mojave : “The second night of observing produced even more activity than the first. The unusual number of EGE’s is probably due to misidentified ORI’s. The high number of LMI’s is probably real although we saw less than half this many visually.”

Obs Date(UT)TotTime TOT SPO NTA STA ORI OUI SSA EGE LMI
TUS Oct-22  11h 09m 157  29  3   3  113  1   2   5   1
SDG Oct-22  04h 07m 234  54  7   9  137  4   -   11  12

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)
NTA/STA – Northern and Southern Taurids (includes Antihelions)
ORI – Orionids
ZTA – Zeta Taurids
OUI – October Ursae Minorids
SSA – Sigma Arietids
EGE – Epsilon Geminids
LMI – Leonis Minorids

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