(meteorobs) Obs: 13/14 Dec 2008

[pmartsching at mchsi.com]

It was mostly cloudy in the evening then overcast the rest of the night of Dec 12/13 here in central Iowa.  The afternoon of 13 Dec it was mostly cloudy at sunset.  Later I checked the satellite infrared and it looked like there was a possibility of a couple hour gap between masses of cloud moving SW to NE.  I was at the McFarland Park Conservation Center Parking lot and set up by 8:00 pm CST.  Warm wind was blowing from the SE over a thin layer of snow.  It finally cleared by 03:30 UT (09:30 pm CST) so I was able to begin possibly useful observing.

I picked out and charted some of the faintest stars I could see in my field of view in the bright Moon light and later checked their magnitudes so I think the average limiting magnitudes aren't far wrong.

Any meteor of typical Geminid velocity coming from the general direction of Caster and Pollux was considered a GEM; it is likely that sporadics are in the Geminid counts, but considering the poor limiting magnitude and the time of night I don't think there are enough to worry about.

With the exceptions of one Sigma Hydrid meteor and one Antihelion meteor all meteors not counted as Geminids were considered to be sporadics.  Considering the terrific glare of the Moon near the radiant, the wind, holding my umbrella to shield my face from the Moon light, and the frequent interference of patches of Moon lit cloud, I didn't think this was the time to resort to an alignment cord.

03:30 - 04:30 UT 40 degrees F; wind SE 10 mph; snow on ground; average limiting magnitude 4.2; average cloud cover 5%; facing N 45 degrees; using black umbrella to block Moon light and the wind; total teff 1.0 hour
Sigma Hydrid: one: 0
Geminids: fourteen: -4; -2; -1; 0(2); +1(3); +2(4); +3(2)
Sporadics: two: +2; +3
Total meteors: seventeen

04:30 - 05:30 UT 40 degrees F; wind SE 10 mph; snow on ground; average limiting magnitude 4.1; average cloud cover 10%; facing North 45 degrees; using black umbrella to block Moon light and wind; total teff 1.0 hour
Antihelion: one: -4
Geminds: twenty-four: -3(2); -2(3); -1; 0(4); +1(4); +2(5); +3(5)
Sporadics: one: +2
Total meteors: twenty-six

It quickly became overcast after 05:30.  At 05:39 I saw a mag -3 GEM while packing up to leave.

After I got home I checked out the satellite infrared again and noticed that possibly another clear spot might come through so I went back out and waited.  No really clear spot ever came, but I'm glad I went back out because in the first five minutes I saw three nice GEM's: mag. 0, -5 & -3.  The -5 had a train lasting a couple seconds in the bright Moon light.  

07:00-08:15 UT; 39 degrees F; wind SE 9 mph; snow on the ground; average limiting magnitude 3.9; average cloud cover 30%; facing NNE 45 degrees 07:00 - 07:45; facing NE 45 degrees 07:45 - 08:15; used black umbrella to black bright Moon light; total teff 1.25 hour.
Sporadics: two: +2; +3
Geminids: twenty-four: -5; -3; -2(3); -1(3); 0(7); +1(5); +2; +3(3)
Total meteors: twenty-six (one hour and fifteen minutes)

The Geminids put on their usual good show of bright post-max meteors!