(meteorobs) Obs: 13/14 December 2007

[pmartsching at mchsi.com]

14 December 2007 03:10-07:10 UT (CST 13/14 Dec 09:10 pm - 01:10 am)

Paul Martsching
McFarland Park 4 miles NE of Ames, Story County, Iowa
Long: 93 deg 34 min W  Lat: 42 deg 05 min N  Elevation: ~1,040 feet
Method: Visual; paper, pencil & talking clock

The weather has been terrible for meteor observing since November 13th.  The sky
cleared about 9 pm.  During the four hours of observing it was never truly
"clear".  There was some haze - the sky glow over Ames, Nevada and Story City
was brighter than usual.  This often happens when there is snow on the ground
and the temperature gets a little above freezing in the day time.  Besides the
horizon haze there was always a little haze or extremely thin clouds along with
spreading jet contrails drifting thru the sky.  Also several times clouds were
passing over Ames in the Southwest reflecting light into the Eastern sky.  I saw
quite a few Geminids in spite of the not-very-good limiting magnitude.

At one point I was thinking that I'd seen no Geminid fireballs (mag. -4 or
brighter) and thought maybe it was too many hours before the peak to expect to
see any.  Less that five minutes later the brightest Geminid I have ever seen
appeared - I estimated it at mag. -9.  It ended behind some thin cloud low in
the South, so tho it had some train, I cannot say anything for certain about
train duration.

To my eyes the Geminids are perhaps the least colorful of the brighter meteor
showers.  Most of the negative magnitude Geminids look just white to me.  This
night I saw several yellow and orange Geminids and the bright fireball started
out red and ended blue-white.  In the past I have seen very blue and very green
Geminids, but these are extremely rare.

Monocerotids: While watching the Geminids, Sigma Hydrids, Coma Berenicids and
Antihelion meteors I sometimes forget about the Monocerotids.  If I saw any they
are counted among the few sporadics.

03:10-04:10; 28 degrees F; wind NW 10 mph; "clear" see above; snow on ground;
average limiting magnitude 5.4; facing East 45 degrees; total teff 1.0 hour
Antihelion: one: +1
Coma Berenicid: none
Geminids: six: +1(3); +2, +3, +4
Sigma Hydrid: none
Sporadics: two: 0; +1
Total meteors: nine

04:10-05:10; 24 degrees F; wind N 12 mph; "clear"; snow on ground; average
limiting magnitude 5.4; facing East 45 degrees; total teff 1.0 hour
Antihelion: one: -2
Coma Berenicid: one: -4  (orange with 1 second train)
Geminids: twenty-three: -3; -2; -1(2); 0(4), +1(4); +2(7); +3(3), +4
Sigma Hyrdrid: none
Sporadics: none
Total meteors: twenty-five

05:10-06:10; 20 degrees F; wind N 10 mph; "clear"; snow on ground; average
limiting magnitude 5.4; facing East 45 degrees; total teff 1.0 hour
Antihelion: one: +2
Coma Berenicid: none
Geminids: twenty-eight: -3; -2; 0(5); +1(7); +2(6); +3(7); +4
Sigma Hydrid: one: -1
Sporadics: four: +2(3); +3
Total meteors: thirty-four

06:10-07:10; 18 degrees F; wind NW 12 mph; "clear"; snow on ground; average
limiting magnitude 5.2; facing East 45 degrees; total teff 1.0 hour
Antihelion: none
Coma Berenicid: none
Geminids: thirty-eight: -9; -3; -2(2); -1(2); 0(6); +1(6); +2(9); +3(10); +4
Sigma Hydrid: one: +1
Sporadics: two: 0; +3
Total meteors: forty-one

Quit because sky becoming mostly cloudy.  Comet Holmes was surprisingly easy to
see naked-eye in spite of the sky conditions.