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(meteorobs) Oct 21 Observations and analysis - LMI?
It has been a while since I observed under good conditions,
struggling against low clouds, haze, light pollution here on
overpopulated Oahu. So, I decided to spend friday night on the top
of Haleakala. What a pleasure to see again a near-perfect sky with
the dazzling milky way, Gegenschein and Zbands! Of course
moonlight began to interfere after 0130 local time, even more
reason to go to the clearest skies possible.
I observed in 3 sessions, the first 1hr Teff just before moonrise, the
2nd at 0230 local and the last 0.5hr before sunrise. Overall, I saw
61 meteors in 2.5hr. The Orionids were not as impressive as I
expected, only 17 total. The Anthelions were almost as numerous
with 15. Also, very few bright meteors of any kind. Only 4 meteors
were brighter than mag 2!
I had more difficulty than usual associating meteors with showers,
because of the proximity of the ORI EGE and APX radiants, and all
had very similar velocity! As a result, I believe my counts of these 3
are less accurate than usual. In fact, I think there may actually
have been a few more EGE than reported, because I may have
placed too many "close calls" in the APX or ORI bin.
With this caveat in mind, I did a simple analysis of ZHR and found
ORI somewhere between 10-15, compared with ANT tending to be
<10. EGE ZHR were <5, but their raw counts were very low, and
may have been underestimated, as stated above...
An interesting note: Leo Minorids activity was seen during the last
0.5hr near dawn. Even though the raw count was low, I still get a
surprisingly good adjusted ZHR of about 13 for this "unknown"
shower! Has anyone else looked for this obscure radiant?
Aloha!
Mike Linnolt
REPORT FOLLOWS:
------------------------------
OBS: Mike Linnolt (LINMI)
DATE: Oct 21, 2000
TIME: 1000 - 1500 UT (12:00am - 05:00am HST Oct 20/21)
LOC: Haleakala NP, Maui, HI (20° 40' N, 156° 20m W)
ELEV: 3000m
Conditions: Sky clear. Temp 40F. RH <20%. Winds Moderate.
METHOD: Paper
Observing Periods Summary:
==========================
# Period(UT) FOV Teff F LM ORI EGE LMI ANT APX SPO
---------- --- ---- - -- --- --- --- --- --- ---
1 1000-1104 01h +00 1.00 1.00 6.6 7 0 0 7 5 6
2 1230-1333 03h +00 1.00 1.00 6.0 6 1 0 4 2 5
3 1427-1500 05h +00 0.50 1.00 5.9 4 1 2 4 3 4
ANT = Anthelion radiant = NTA/STA
2 Breaks
Periods Detail:
===============
Period #1:
----------
Mag -3 -2 -1 0 +1 +2 +3 +4 +5 +6 elev r ZHR
--------------------------------------------------------------
ORI: 0 0 0 0 1 2 1 1 2 0 = 7 30 2.9 12.6
EGE: 0 0 0 0 0 0 0 0 0 0 = 0
LMI: 0 0 0 0 0 0 0 0 0 0 = 0
NTA: 0 0 0 0 0 0 0 3 1 0 = 4 77 2.3\
STA: 0 0 0 0 0 1 1 1 0 0 = 3 77 2.3/ 6.6
APXn 0 1 0 0 0 0 1 1 1 1 = 5
APXs 0 0 0 0 0 0 0 0 0 0 = 0
SPO: 0 0 0 0 0 0 1 2 2 1 = 6
DEAD TIME: 4 min
Note:
Period #2:
----------
Mag -3 -2 -1 0 +1 +2 +3 +4 +5 +6 elev r ZHR
--------------------------------------------------------------
ORI: 0 0 0 0 1 0 2 2 1 0 = 6 65 2.9 11.3
EGE: 0 0 0 0 0 1 0 0 0 0 = 1 56 3.0 2.1
LMI: 0 0 0 0 0 0 0 0 0 0 = 0
NTA: 0 0 0 0 0 0 0 0 1 0 = 1 65 2.3\
STA: 0 0 0 1 0 0 1 1 0 0 = 3 65 2.3/ 6.7
APXn 0 0 0 0 0 0 0 1 0 0 = 1
APXs 0 0 0 0 0 0 0 0 1 0 = 1
SPO: 0 0 0 0 0 1 1 0 3 0 = 5
DEAD TIME: 3 min
Note: Moonlight interference reduced LM.
Period #3:
----------
Mag -3 -2 -1 0 +1 +2 +3 +4 +5 +6 elev r ZHR
--------------------------------------------------------------
ORI: 0 0 0 0 0 0 1 2 1 0 = 4 86 2.9 15.2
EGE: 0 0 0 0 0 0 0 1 0 0 = 1 78 3.0 4.0
LMI: 0 0 0 0 0 0 1 1 0 0 = 2 32 ?2.5 13.0
NTA: 0 0 0 0 0 1 1 1 0 0 = 3 42 2.3\
STA: 0 0 0 0 0 0 0 1 0 0 = 1 42 2.3/ 19.7
APXn 0 0 0 0 0 0 0 0 0 0 = 0
APXs 0 0 0 0 0 0 1 2 0 0 = 3
SPO: 0 0 0 0 0 1 1 1 1 0 = 4
DEAD TIME: 3 min
Note: Moonlight slightly worse.
END OF REPORT.
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