(meteorobs) December 22, 2004 Meteor Observations From California

[Robert Lunsford]

I viewed from the Deerhorn Valley Helipad this morning. Conditions were less 
than ideal. The low clouds that obscured the city lights on the previous 
morning were now gone. There was a strong glow in the western half of the 
sky forcing me to view toward the northeast. On top of that there was also 
cirrus clouds present that caused me to shift my field of view throughout 
the night. I estimated that roughly one quarter of my total field of view 
was affected during the first hour and roughly half of my field was affected 
during the second hour. The meteors I did see tonight were quite bright. 
Only one Ursid was seen during the first 52 minutes of viewing. Three Ursids 
were seen in the next fifteen minutes and between 1243 and 1308, five more 
Ursids were seen. While these are low numbers, this is the best Ursid 
showing for me in several years. Four COM's were also seen and only one 
possible December Leonid was seen. The highlight of the session was a -2 
Coma Berenicid that shot high overhead heading west, leaving a seven second 
persistent train.

December 22 , 2004

1100-1204 UT   1.00   6.85    1.33   0 ANT  1 COM  3 URS   3  SPO
                                                          7 TOTAL

1204-1311 UT   1.00   6.61    2.00   0 ANT  3 COM  6 URS  7 SPO
                                                          16 TOTAL

TOTALS:           2.00   6.73    1.67   2 ANT  3 COM  1 URS  21 SPO
                                                          27  TOTAL METEORS

The first column gives the period watched in Universal Time (UT)
which is PST + 8 hours. The second column gives the percent of that
particular hour actually spent observing the sky (1.00 = 100%, 0.99
= 99%). Time is lost for breaks and plotting.  No breaks were taken.
The third column gives the average limiting magnitude estimated during
each period. The fourth column lists the correction for cloudiness where
a clear sky = 1.00 and 50 percent obscuration = 2.00. The last several
columns list the activity for expected active radiants during each period.
Quite often no activity is observed and rates equal zero. Tonight I was
facing north northeast with my field of view centered at 50 degrees 
altitude.
 ANT = Antihelion radiant,COM = Coma Berenicids, URS = Ursids and
 SPO = Sporadics (random activity).

Location: Deerhorn Valley Helipad 116 40' 04" W 32 44' 52" N  ELE = 750 m

Bortle Scale Estimate: Class III (Rural Site)

Beginning Temperature/Relative Humidity: 39 F (4 C)  56%
Ending              "               "             "        40 F (4 C)  60%

MAGNITUDES OF INDIVIDUAL METEORS PER RADIANT:

COM  -2 (1) +1 (1) +2 (2) +3 (0) +4 (0) +5 (0)    AVG: +0.57

URS:    0 (2) +1 (2) +2 (1) +3 (2) +4 (2) +5 (0)    AVG: +2.00

SPO:  -1 (2) +1 (0) +2 (2) +3 (3)  +4 (2) +5 (1)    AVG: +2.40


Bob Lunsford
San Diego, CA