(meteorobs) Geminids I - 2007 Dec 7/8

Bruce McCurdy bmccurdy at telusplanet.net
Sun Dec 16 21:53:43 EST 2007


    As my project to observe every major meteor shower in 2007 draws to a 
close, I find myself ever more obsessive in my pursuit. As the Geminids 
approached I hoped to observe the rise and fall of the shower, preferably 
every night from Dec. 10/11 to the 14/15.  In the end only the first and 
last of those nights was clear. But I found the clear skies beckoning a few 
nights earlier on the 7/8, and I managed to get a couple of hours in, 
snagging a few early Gems in the process. In total I had three sessions and 
10 hours Teff over the course of one week.

    For the first time this winter I had to deal with snow cover, which in 
2006-07 stretched through six full months -- literally from the Orionids to 
the Lyrids (and I have the audio tapes to prove it)! But by early December 
winter was here with a vengeance, with temperatures dropping to -25° C. The 
sky was "white" with ice crystals reflecting the bright ground, so limiting 
magnitude was a modest 5.3-5.5. I took a few readings with our club's Sky 
Quality Meter before it succumbed to the cold and called it a night. (It 
worked fine again once it warmed up.) I faced SSW and watched Mars cruise 
through my field of view during the session. The Red Planet was surrounded 
by three radiants, although there was no Moncoerotid activity for me on this 
night.

    I was extrememly tired during this session, and saw a number of illusory 
streaks that I dubbed the Phantasmagorids. In particular when I moved my 
head and then stopped the stars seemed to blur for a split second before 
stabliziling. I attributed this to observation of neurons in the act of 
freezing. :)

    Bruce
    *****

Observer: Bruce McCurdy, MCCBR
Location: Range Rd 264/Sanctuary Road near Devon, AB @ 
53.371110, -113.787530
Time: 2007 December 8, 09:00-11:15  UT; Teff = 2.0 hours
Limiting magnitude = 5.3 to 5.5 (SQM = ~20.0)
Method: visual, microscassette recorder and talking watch
Comments in "quotations" are verbatim transcripts
/ = description of meteor in length and duration
~ = description of persistent train in length and duration

Active radiants:
Antihelion (ANT) 05:56 (089) +23
Monocerotids (MON) 06:36 (099) +08
Geminids (GEM) 07:08 (107) +33
Sigma Hydrids (HYD) 08:20 (125) +02
Coma Berenicids (COM) 11:16 (169) +27

09:00 - 10:10; clear; avg. LM = 5.5; facing south 60°; Teff = 1.0 hour
Time    type    mag    comment
----------------------------------
09:00    start
09:02    GEM    +2
09:07    GEM    +5
09:16    SPO    -2    bronze, v.swift
09:25    SPO    +4
09:29    ANT    +4
09:30    SPO    +4
09:30 - 09:40    "Comet break"
09:41    SPO    +4
09:44    ANT    +2
09:44    GEM    +4
09:46    HYD    +2
10:06    SPO    +4
10:07    HYD    +3    near radiant, slow, v.pretty
10:09    SPO    +2
***
2 ANT: +2, +4
3 GEM: +2, +4, +5
2 HYD: +2, +3
6 SPO: -2, +2, +4(4)
Total meteors: thirteen
***

10:10 - 10:20    break

10:20 - 11:20; clear; avg. LM = 5.3; facing south 60°; Teff = 1.0 hour
Time    type    mag    comment
----------------------------------
10:26    SPO    -1    "That one reminded me of a Perseid"
10:39    SPO    +1    / 0.5 s, 10°; ~1.5 s, 10°
10:44    HYD    +2    / 0.5 s; near radiant right by Alphard, wake
11:04    GEM    -1    brief wake, blue-ish
11:06    ANT    +4
11:10    SPO    +3
11:12    SPO    +2    swift; possible DLM??
***
1 ANT: +4
1 GEM: -1
1 HYD: +2
4 SPO: -1, +1, +2, +3
Total meteors: seven
*****

Observing summary:
Teff = 2.0 hours

3 ANT: +2, +4(2)                                [avg. = +3.3]
4 GEM: -1, +2, +4, +5                        [avg. = +2.5]
3 HYD: +2(2), +3                                [avg. = +2.3]
10 SPO: -2, -1, +1, +2(2), +3, +4(4)   [avg. = +2.1]
Total meteors: twenty
***** 




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